BEIJING — China's foreign minister Friday called the United States the "troublemaker of the world" and threatened to "sever the black hands" supporting protests in Hong Kong, in strident language that was markedly at odds with rosy trade talk from Washington.

Just hours after White House officials said that President Trump had approved a proposed U.S.-China trade deal, China’s top diplomat took to a stage in Beijing to say that the United States needed to “calm down” and step back from confrontation.

Washington had “launched deliberate attacks and defamation” against China over its “territorial sovereignty, national dignity and core interests,” Wang Yi told a diplomatic conference in Beijing, to an extent that the United States appeared “almost paranoid.”

He was referring particularly to U.S. support for pro-democracy protesters in Hong Kong and condemnation of China’s detention of more than 1 million Muslims in political reeducation camps. Beijing has repeatedly accused American agents with “black hands” of fomenting unrest in Hong Kong.

“We are willing to resolve the contradictions and differences with the U.S. through dialogue and discussions based on equality and mutual respect, but we will never accept unilateral sanctions or bullying,” he said, according to reports from the conference.

Earlier, Trump advisers said he had agreed to a trade deal under which the White House would reduce tariffs on Chinese goods in return for China buying $50 billion worth U.S. farm goods, tightening its intellectual property protections and opening its financial services markets.

The next round of American tariffs, on the remaining $160 billion in Chinese goods that have not been hit with duties, were scheduled to take effect on Sunday. Those tariffs have been delayed, and the existing tariffs on $360 billion of Chinese products will be reduced, the advisers said.

China did not directly comment Friday on the purported deal. The Commerce Ministry, the department that usually releases news about the trade talks, did not respond to calls and faxes requesting comment.

“Chinese ministries will be guarded until the formal signing,” said Tao Wang, chief Asia economist at UBS investment bank.

“Postponing or canceling the December tariff hike is the minimum China would accept,” she said. “I think China would like the September tariffs to be removed completely.”

At the Foreign Ministry, spokeswoman Hua Chunying demurred when asked if the two sides had reached a deal, saying that an “agreement has to be mutually beneficial.”

“As soon as reports suggesting the phase one deal was reached emerged, the major stock markets in the U.S. and Europe jumped. This illustrates that a deal through negotiation is beneficial to both nations and their peoples, and it is what the international community wants,” she said.

China’s currency rose to its highest level in more than four months against the U.S. dollar, while stock markets in Shanghai, Shenzhen and Hong Kong all soared on Friday, a sign of investor optimism that the protracted trade war might be coming to a resolution.

Trump has described the agreement as a “phase one” deal, but Andrew Batson, an economist at the Gavekal Dragonomics consultancy, said he did not expect a phase two.

“I don’t know what else could happen here,” he said. “To be fair to the Chinese, they have done a lot on structural issues this year on their own initiative, because they don’t like to be forced to do things in negotiations.”

Both Batson and Wang, the UBS economist, pointed to significant legal reforms to protect intellectual property, opening in the financial services sector, and reducing subsidies for electric vehicle and solar panel manufacturers.