WASHINGTON (AP) — President Donald Trump said Friday there was “no need to rush” to get a trade deal with China, hours after he raised tariffs on $200 billion in Chinese goods, escalating a battle over China’s technology ambitions.

U.S. and Chinese negotiators met briefly Friday in an effort to revive negotiations even as the Trump administration increased duties on nearly half of Chinese imports to 25% from 10%. China’s Commerce Ministry said it would impose “necessary countermeasures” but gave no details.

The increase went ahead even after American and Chinese negotiators began more talks in Washington on Thursday aimed at ending a dispute that has disrupted billions of dollars in trade and shaken global financial markets. After a short session on Friday, the lead Chinese negotiator, Vice Premier Liu He, left the Office of the U.S. Trade Representative about midday, though it was not immediately clear whether talks had ended. U.S. Trade Representative Robert Lighthizer and Treasury Secretary Steven Mnuchin shook hands with Liu as he left.

“The risk of a complete breakdown in trade talks has certainly increased,” Michael Taylor of Moody’s Investors Service said in a report.

But Trump tweeted that his tariffs, which went into effect just after midnight, “will bring in FAR MORE wealth to our Country than even a phenomenal deal of the traditional kind. Also, much easier & quicker to do.”

In fact, tariffs are taxes paid by U.S. importers and often passed along to consumers and companies that rely on imported components.

The developments sent stocks tumbling on Wall Street.

American officials accuse Beijing of backtracking on commitments made in earlier rounds of negotiations.

“China deeply regrets that it will have to take necessary countermeasures,” said a Commerce Ministry statement.

The administration bought a little extra time for talks to work: According to the filing Wednesday in the Federal Register, the tariff hike won’t hit goods that have already left Chinese ports before Friday’s deadline.

So the tariffs won’t start taking affect until those shipments complete the three- to four-week voyage across the Pacific Ocean.

U.S. business groups appealed for a settlement that will resolve chronic complaints about Chinese market barriers, subsidies to state companies and a regulatory system they say is rigged against foreign companies.

American companies disagree with tariff hikes but “are supportive of the idea in the short term if it helps us get to a strong, enforceable, long-term agreement that addresses structural issues,” said Greg Gilligan, the deputy chairman of the American Chamber of Commerce in China.

The latest increase extends 25% duties to a total of $250 billion of Chinese imports, including $50 billion already taxed at 25% before the new hike. Trump said Sunday he might expand penalties to all Chinese goods shipped to the United States.

Beijing retaliated for previous tariff hikes by raising duties on $110 billion of American imports. But regulators are running out of U.S. goods for penalties due to the lopsided trade balance.

Chinese officials have targeted operations of American companies in China by slowing customs clearance for them and stepping up regulatory scrutiny that can hamper operations.

The latest U.S. increase might hit American consumers harder, said Jake Parker, vice president of the U.S.-China Business Council, an industry group. He said the earlier 10% increase was absorbed by companies and offset by a weakening of the Chinese currency’s exchange rate.

A 25% hike “needs to be passed on to the consumer,” Parker said. “It is just too big to dilute with those other factors.”

Despite the public acrimony, local Chinese officials who want to attract American investment have tried to reassure companies there is “minimal retaliation,” he said.

“We’ve actually seen an increased sensitivity to U.S. companies at the local level,” he added.

The higher U.S. import taxes don’t apply to Chinese goods shipped before Friday. By sea, shipments across the Pacific take about three weeks, which gives negotiators a few more days to reach a settlement before importers may have to pay the increased charges.

The negotiators met Thursday evening, and Lighthizer, Mnuchin and Liu held a working dinner.

Liu, speaking to Chinese state TV on his arrival in Washington, said he “came with sincerity.” He appealed to Washington to avoid more tariff hikes, saying they are “not a solution” and would harm the world.

“We should not hurt innocent people,” Liu told CCTV.

At the White House, Trump said he received “a beautiful letter” from Chinese President Xi Jinping and would “probably speak to him by phone.”

The two countries are sparring over U.S. allegations Beijing steals technology and pressures companies to hand over trade secrets in a campaign to turn Chinese companies into world leaders in robotics, electric cars and other advanced industries.

This week’s setback was unexpected. Through late last week, Trump administration officials were suggesting that negotiators were making steady progress.

U.S. officials say they got an inkling of China’s second thoughts about prior commitments in talks last week in Beijing but the backsliding became more apparent in exchanges over the weekend. They wouldn’t identify the specific issues involved.

A sticking point is U.S. insistence on an enforcement mechanism with penalties to ensure Beijing lives up to its commitments. American officials say China has repeatedly broken past promises.

China wants tariffs lifted as soon as an agreement is reached, while U.S. officials want to keep them as leverage to ensure compliance.

“A real enforcement mechanism is critical,” the American Chamber of Commerce in Shanghai said in a statement.

Also Thursday, Canadian Prime Minister Justin Trudeau urged Trump in a phone call to press China to release two Canadians who have been held for five months.

The men were detained in apparent retaliation after Canada arrested an executive of Chinese tech giant Huawei on U.S. charges of bank fraud.