The United States and China called a truce in their trade war on Saturday after President Trump agreed to hold off on new tariffs and President Xi Jinping pledged to increase Chinese purchases of American products.
Still, the handshake deal between Mr. Trump and Mr. Xi, after what the White House called a “Highly successful meeting,” pauses what was becoming a headlong race toward economic conflict.
In a significant concession, Mr. Trump will postpone a plan to raise tariffs on $200 billion worth of Chinese goods to 25 percent, from 10 percent, on Jan. 1.
The Chinese agreed to an unspecified increase in their purchases of American industrial, energy and agricultural products, which Beijing hit with retaliatory tariffs after Mr. Trump targeted everything from steel to consumer electronics.
The countries set an ambitious deadline of 90 days to reach a broader trade agreement, with the White House warning that if they did not come to terms by then, Mr. Trump would raise the existing tariff rate to 25 percent.
“The relationship is very special – the relationship that I have with President Xi,” Mr. Trump told reporters as he sat across a long table from the Chinese leader before dinner was served.
For Mr. Trump, the agreement was an upbeat end to his subdued visit to the G-20 meeting.
On his second day in Buenos Aires, Mr. Trump said little about global security or diplomacy, keeping a single-minded focus on trade.
The outcome remained in doubt until the end, when Mr. Trump, flanked by his top aides, sat down with Mr. Xi and his aides to a meal of grilled sirloin and bottles of Malbec.
Mr. Trump had veered from optimism to wariness about a deal, sometimes in the course of a single statement.
As part of a series of tit-for-tat moves, Mr. Trump said he would raise the tariff for all goods to 25 percent and consider imposing tariffs on an additional $267 billion worth of exports.
Some experts said the forces Mr. Trump had set in motion with Beijing would be hard to restrain.
“A halt in the tariff wars will be welcome but won’t alter the fundamental collision course that Trump and Xi seem to be on,” said Daniel M. Price, a former trade adviser to President George W. Bush.
The W.T.O. is a favorite target of Mr. Trump because he believes it crimps America’s ability to use tariffs and allows countries like China to cheat.
Mr. Trump’s experience was less comfortable.
Mr. Trump’s stubborn defense of Prince Mohammed has aggravated tensions with Turkey, which shared an audio recording of the attack on Mr. Khashoggi with the director of the C.I.A., Gina Haspel, and demanded a fuller accounting from the Saudis of what happened.
On Saturday, Mr. Trump met with Turkey’s leader, Recep Tayyip Erdogan, but the White House closed the session to even the brief picture-taking opportunity that usually accompanies these meetings.
At a dinner for the leaders on Friday night, the White House said Mr. Trump spoke informally with Mr. Putin.
There were photos of the president and the first lady, Melania Trump, seated at the long table, separated from Mr. Putin by Mr. Xi and his wife, Peng Liyuan.