WASHINGTON — U.S. Secretary of State Rex Tillerson said Thursday that China has threatened to impose sanctions on North Korea if it conducts further nuclear tests.

“We know that China is in communications with the regime in Pyongyang,” Tillerson said on Fox News Channel. “They confirmed to us that they had requested the regime conduct no further nuclear test.”

Tillerson said China also told the U.S. that it had informed North Korea “that if they did conduct further nuclear tests, China would be taking sanctions actions on their own.”

Earlier Thursday, the senior U.S. Navy officer overseeing military operations in the Pacific said the crisis with North Korea is at the worst point he’s ever seen, but he declined to compare the situation to the Cuban missile crisis decades ago.

“It’s real,” Adm. Harry Harris Jr., commander of U.S. Pacific Command, said during testimony before the Senate Armed Services Committee.

Harris said he has no doubt that North Korean leader Kim Jong Un intends to fulfill his pursuit of a nuclear-tipped missile capable of striking the United States. The admiral acknowledged there’s uncertainty within U.S. intelligence agencies over how far along North Korea’s nuclear and missile programs are. But Harris said it’s not a matter of if but when.

“There is no doubt in my mind,” Harris said.

China’s foreign ministry had no immediate comment on Tillerson’s remarks on new sanctions, but a spokesman Thursday said Beijing remained committed to implementing sanctions imposed under U.N. Security Council resolutions.

“And the reason that China implements relevant resolutions is to fulfill our due international obligation rather than being pressured by any outside parties,” Geng Shuang said at a daily briefing.

China has consistently called for an end to North Korea’s nuclear weapons program, but says it opposes unilateral sanctions imposed without a U.N. mandate. China in January suspended coal imports from the North for the rest of the year, but it did so following the passage of a Security Council resolution capping Pyongyang’s coal exports.

Other economic activity with North Korea remains robust.

Still, Beijing has been increasing pressure on North Korea, and would be willing to impose punitive measures unilaterally in the event of another nuclear test, said Cheng Xiaohe, an associate professor at Renmin University’s School of International Studies in Beijing.

“So Tillerson’s comments are correct — but be careful, China does so for China’s national interest, not as a result of U.S. pressure,” Cheng said.

The Trump administration has declared that all options, including a targeted military strike, are on the table to block North Korea from carrying out threats against the United States and its allies in the region. But a pre-emptive attack isn’t likely, U.S. officials have said, and the administration is pursuing a strategy of putting pressure on Pyongyang with assistance from China, North Korea’s main trading partner and the country’s economic lifeline.

With international support, the Trump administration said Thursday it wants to exert a “burst” of economic and diplomatic pressure on North Korea that yields results within months to push the communist government to change course from developing nuclear weapons.

Susan Thornton, the acting top U.S. diplomat for East Asia, said there’s debate about whether Pyongyang is willing to give up its weapons programs. She said the U.S. wants “to test that hypothesis to the maximum extent we can” for a peaceful resolution.

But signaling that military action remains possible, Thornton told an event hosted by the Foundation for Defense of Democracies — the Washington think tank has advocated tougher U.S. policies on Iran and North Korea — that the administration treats North Korea as its primary security challenge and is serious that “all options are on the table.”

“We are not seeking regime change and our preference is to resolve this problem peacefully,” Thornton said, “but we are not leaving anything off the table.”

Tillerson took a similar stand in the Fox News interview Thursday, saying: “We do not seek regime change in North Korea. … What we are seeking is the same thing China has said they seek — a full denuclearization of the Korean peninsula.”

In a separate interview with National Public Radio, Tillerson said the U.S. remains open to holding direct negotiations with North Korea.

“But North Korea has to decide they’re ready to talk to us about the about the right agenda, and the right agenda is not simply stopping where they are for a few more months or a few more years and then resuming things,” he said, according to excerpts of an interview that will air Friday morning. “That’s been the agenda for the last 20 years.”

Multi-nation negotiations with North Korea on its nuclear program stalled in 2008. The Obama administration attempted to resurrect them in 2012, but a deal to provide food aid in exchange for a nuclear freeze soon collapsed.

The House GOP leadership announced late Thursday that it would vote next week on new sanctions against North Korea that would target its shipping industry and those who employ North Korean slave labor abroad.

“The time for waiting on North Korea to get its act together is over. Congress has led the effort to institute tough and far-reaching sanctions against Pyongyang,” said House Majority Leader Kevin McCarthy, R-Calif.

In a show of military might, the U.S. has sent a massive amount of American weaponry to the region. A group of American warships led by the aircraft carrier USS Carl Vinson is in striking range of North Korea “if the president were to call on it,” Harris told the committee. A U.S. missile defense system called Terminal High-Altitude Area Defense is being installed in South Korea.

Harris said he has adequate forces to “fight tonight” against North Korea if that were to become necessary.

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Associated Press writers Matthew Pennington in New York and Matthew Brown in Beijing contributed to this report.

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Contact Richard Lardner on Twitter: http://twitter.com/rplardner

Copyright 2017 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

President Trump told the leaders of Canada and Mexico on Wednesday that the United States would not be pulling out of the North American Free Trade Agreement “at this time,” opening the door to future negotiations on the same day that Trump was considering signaling a strong intent to withdraw as a potential way of bringing the parties together at the deal-
making table.

Trump spoke with Mexican President Enrique Peña Nieto and Canadian Prime Minister Justin Trudeau late Wednesday afternoon after reports circulated during the day that the president was contemplating withdrawing from NAFTA.

“President Trump agreed not to terminate NAFTA at this time and the leaders agreed to proceed swiftly, according to their required internal procedures, to enable the renegotiation of the NAFTA deal to the benefit of all three countries,” the White House said in a statement late Wednesday.

News that Trump was weighing withdrawing from NAFTA drew sharp criticism from several Republican leaders, including Sen. Jeff Flake (R) and Sen. John McCain (R). McCain tweeted that Trump “shouldn’t abandon this vital trade agreement.”

Earlier, three people familiar with the matter said Trump is seriously considering signing a document within days that would signal his intent to withdraw the United States from the agreement within six months.

If signed, the letter would begin a formal process that could see the United States exit the 23-year-old trade pact with Canada and Mexico, ratcheting up tensions among neighboring nations.

Signing the document does not require Trump to withdraw from NAFTA after six months, but it is a required step if he plans to eventually do so. The White House is expected to soon take a separate step by signing a letter to Congress that would notify lawmakers of the administration’s intention to renegotiate NAFTA. By taking both steps, the White House would give itself more flexibility to choose a different outcome in several months.

Any move by Trump on NAFTA would not come as a surprise. The president made criticism of NAFTA one of the main topics of his campaign last year, calling the pact “a disaster for our country” and saying it “had to be totally gotten rid of.”

But the NAFTA issue did seem to lose some urgency after the first few weeks of Trump’s presidency as his administration focused on other topics.

“Some people were hopeful that just like he revised his views on NATO, he’d revise his views on this,” said Hoyt Bleakley, associate professor of economics at the University of Michigan. “But clearly he hasn’t.”

In recent days Trump also has taken a harder line with Canada, blasting a recent change in the dairy pricing policy there that mostly dealt with a cheese-making product called ultrafiltered milk. In Wisconsin last week, Trump called Canada’s dairy pricing scheme “another typical one-sided deal against the U.S.” Canada disputed that.

And the Commerce Department said Monday that it would begin charging a tariff on the import of softwood lumber from Canada into the United States, alleging Canada was improperly subsidizing its domestic timber firms.

But there was no panic over the fate of NAFTA in the Calgary offices of the Canadian Cattlemen’s Association, whose members sell and buy plenty of beef cattle across the border.

“This is his typical way of doing things — saying completely unreasonable things as a negotiating posture,” said John Masswohl, the trade group’s director of government and international relations.

Masswohl said he watched how Trump handled issues at the Carrier plant in Indiana and with Ford’s plans to build car models in Mexico. He sees similar rhetoric in Trump’s approach to NAFTA.

“I’ve got to believe this is a negotiating position,” Masswohl said, because the trade pact might need tweaking, but it has been good for both countries.

Separately, the Trump administration Wednesday made another move on trade that seemed aimed at China, launching an investigation into the effect of aluminum imports on U.S. national security interests.

A similar probe, known as a Section 232 investigation, was announced for foreign-made steel last week.

Commerce Secretary Wilbur Ross said Wednesday that Trump would be signing a directive today urging the inquiry.

Ross said aluminum was a national security interest because the metal in its high-purity form is used in military planes such as the F-35 and F-18, plus armor plating for military vehicles and combat vessels. Just one U.S. smelter makes high-purity aluminum, producing enough for peacetime military needs but not enough if the country enters into conflicts, he said.

“It’s very dangerous from a defense point of view to have only one supplier of an absolutely critical element,” Ross said.

Only two U.S. smelters are fully operational today, with eight others having curtailed operations or closed since 2015. Imported aluminum accounted for 55 percent of the U.S. market last year, the largest market share ever and a steep increase over recent years, Ross said.

The largest importers of aluminum into the United States are China followed by Russia, United Arab Emirates and Canada, Ross said.

Aluminum imports from China, in particular, have been a focus of the U.S. government for months. Late last year, a bipartisan group of 12 U.S. senators asked for a national security review of Chinese aluminum giant Zhongwang International Group Ltd.’s proposed $2.3 billion purchase of U.S. aluminum products maker Aleris, alleging the deal would damage the U.S. defense industry.

In January, days before leaving office, President Barack Obama launched a World Trade Organization complaint about Chinese aluminum subsidies that, the United States claimed, gave Chinese companies an unfair advantage.

And last month, U.S. producers of aluminum foil — including the kind used to wrap kitchen leftovers — filed an anti-dumping complaint against China, claiming the United States was being flooded with unfair, cheap imports. Foil prices have declined significantly in recent years “due to widespread and significant underselling of U.S. producers’ prices,” according to the complaint.

A couple of weeks later, Trump’s Commerce Department announced that it was investigating those and other unfair trade claims.

WASHINGTON — The Trump administration told lawmakers Wednesday it will apply economic and diplomatic pressure on North Korea to dismantle its nuclear weapons program, as an extraordinary White House briefing served to tamp down talk of military action against an unpredictable and increasingly dangerous U.S. adversary.

President Donald Trump welcomed Republican and Democratic senators before his secretary of state, defense secretary, top general and national intelligence director conducted a classified briefing. The same team also met with House members in the Capitol to outline the North’s escalating nuclear capabilities and U.S. response options to what they called an “urgent national security threat.”

After weeks of unusually blunt military threats, the joint statement by the agency chiefs said Trump’s approach “aims to pressure North Korea into dismantling its nuclear, ballistic missile and proliferation programs by tightening economic sanctions and pursuing diplomatic measures with our allies and regional partners.” It made no specific mention of military options, though it said the U.S. would defend itself and friends.

The unprecedented meeting in a building adjacent to the White House reflected the increased American alarm over North Korea’s progress in developing a nuclear-tipped missile that could strike the U.S. mainland. A flurry of military activity, by North Korea and the U.S. and its partners on and around the divided Korean Peninsula, has added to the world’s sense of alert.

While tensions have increased since Trump took office, they’ve escalated dramatically in recent weeks as American and other intelligence agencies suggested the North was readying for a possible nuclear test. Although such an explosion hasn’t yet occurred, Trump has sent high-powered U.S. military vessels and an aircraft carrier to the region in a show of force, while the North conducted large-scale, live-fire artillery drills, witnessed by national leader Kim Jong Un, earlier this week.

On Wednesday, South Korea started installing key parts of a contentious U.S. missile defense system that also has sparked Chinese and Russian concerns.

America’s Pacific forces commander, Adm. Harry Harris Jr., told Congress on Wednesday the system would be operational within days. He said any North Korean missile fired at U.S. forces would be destroyed.

“If it flies, it will die,” Harris said.

The Trump administration has said all options, including a military strike, are on the table. But the administration’s statement after briefing senators — all 100 members were invited — outlined a similar approach to the Obama administration’s focus on pressuring Pyongyang to return to long-stalled denuclearization talks. Trump’s top national security advisers said they were “open to negotiations” with the North, though they gave no indication of when or under what circumstances.

The strategy hinges greatly on the cooperation of China, North Korea’s main trading partner.

“China is the key to this,” said Republican Sen. John McCain of Arizona, who got a preview of Trump’s message at a dinner with the president this week.

Democratic Rep. Adam Schiff of California agreed. “I think the best approach for the administration is to bring the maximum pressure to bear diplomatically on China, as well as North Korea, but otherwise to walk softly and carry a big stick,” he told reporters after attending the Capitol Hill briefing Wednesday.

Among the options are returning North Korea to the U.S. state sponsor of terrorism blacklist, which Secretary of State Rex Tillerson said last week was under consideration. His spokesman, Mark Toner, said Wednesday that another tactic is getting nations around the world to close down North Korean embassies and consulates, or suspending them from international organizations.

But sanctions will be the greatest tool at the Trump administration’s disposal. Tillerson is chairing a U.N. Security Council meeting Friday designed to get nations to enforce existing penalties on North Korea and weigh new ones.

Testifying before the House Armed Services Committee, Harris said he expects North Korea to soon be able to develop a long-range missile capable of striking the United States, as Kim has promised. “One of these days soon, he will succeed,” Harris said.

North Korea’s U.N. mission said Wednesday the nation would react to “a total war” with Washington by using nuclear weapons. It vowed victory in a “death-defying struggle against the U.S. imperialists.”

Trump, like presidents before him, faces difficult options. Sanctions haven’t forced Pyongyang to abandon its nuclear efforts, but a targeted U.S. attack to take out its weapons program risks a wider war along a heavily militarized border near where tens of millions of South Koreans live. The threat would extend to nearby Japan, another country North Korea regularly threatens.

China has urged restraint by both Pyongyang and Washington. In Berlin Wednesday, Foreign Minister Wang Yi said North Korea must suspend its nuclear activities, but “on the other side, the large-scale military maneuvers in Korean waters should be halted.” That was a reference to U.S. and South Korean war games.

China opposes the Terminal High-Altitude Area Defense system, or THAAD, being installed in South Korea, rejecting American assurances that it will only target North Korean missiles. Russia also sees the system’s powerful radars as a security threat.

In Beijing, Chinese foreign ministry spokesman Geng Shuang said THAAD would upset the region’s “strategic balance.” China will take “necessary measures to defend our own interests,” he promised.

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Associated Press writers Foster Klug, Hyung-jin Kim and Kim Tong-Hyung in Seoul; Chris Bodeen in Beijing; Richard Lardner, Matthew Lee and Lolita C. Baldor in Washington, and Edith M. Lederer at the United Nations contributed to this report.

Copyright 2017 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.