Summit

The trade war with China has shifted.

After meeting China’s leader, Xi Jinping, on the side lines of the G20 summit, Mr. Trump told reporters on Saturday: “We discussed a lot of things, and we’re right back on track” with trade talks.

Mr. Trump also said that the United States would not impose any new tariffs on Chinese exports while the talks were underway, and that China had agreed to resume broad purchases of American farm products and other goods.

The negotiations broke down seven weeks ago, when the Chinese side said that it could not accept some provisions that had been tentatively agreed to in an incomplete draft. The Saturday developments delay the imposition of 25 percent tariffs on some $300 billion in Chinese imports.

In a more surprising move, Mr. Trump backtracked on a ban on sales of American equipment to Huawei, the Chinese telecom giant. “U.S. companies can sell their equipment to Huawei,” Mr. Trump said, explaining that he wanted to help American companies that had complained about the ban. In exchange, he said, China agreed to buy a “tremendous amount” of American food and agricultural products.

In May, the Commerce Department put Huawei on a blacklist that prohibits American companies from selling equipment to Huawei. The move was a major blow to Huawei, which relies on chips and other equipment from the United States.

Trump and Kim Jong-un may meet again soon.

Mr. Trump said on Saturday that he would visit the Demilitarized Zone that separates North and South Korea on Sunday and publicly invited Mr. Kim, the North’s iron-fisted leader, to meet him there.

In a post on Twitter, Mr. Trump said he would be happy to see Mr. Kim. North Korea indicated on Saturday that it would welcome such a meeting.

[Read more about the stakes of Mr. Trump’s invitation.]

“I consider this a very interesting suggestion, but we have not received any official proposal,” Choe Son-hui, North Korea’s first vice foreign minister, said in a brief statement carried by the North’s official Korean Central News Agency.

Mr. Trump’s tweet caught the diplomatic corps and even his own advisers off balance, since his last meeting with Mr. Kim, in Hanoi, Vietnam, in February, ended in dramatic failure. He told reporters that the tweet had been spontaneous. “I just thought of it this morning,” he said. “We’ll be there, and I just put out a feeler.”

In reality, he had been toying with the idea for days. The Hill, a Capitol Hill news organization, reported on Saturday that Mr. Trump had signaled his interest in the idea during an interview on Monday. The White House asked that his comment not be reported because of security concerns.

Backing the Saudi crown prince sends a powerful signal.

No one is more important to Saudi efforts to rehabilitate Crown Prince Mohammed bin Salman after the murder of Jamal Khashoggi than President Trump, who hosted the de facto Saudi ruler for a personal breakfast on Saturday where he lavished praise on the prince as a reformer opening up his society.

Mr. Trump’s actions sent a powerful signal to the rest of the world and represented a cold-eyed calculation that America’s relationship with Saudi Arabia was more important than the killing of one dissident.

Mr. Trump depicted the prince as a revolutionary figure who is modernizing his country and fighting terrorism. “It’s like a revolution in a very positive way,” Mr. Trump said. “I want to just thank you on behalf of a lot of people, and I want to congratulate you. You’ve done a really spectacular job.”

The president ignored questions from reporters about the prince’s role in the killing and dismemberment of Mr. Khashoggi last October. He also asserted that Prince Mohammed was “very unhappy about” the murder.

Mr. Trump’s own Central Intelligence Agency long ago concluded that the crown prince ordered the murder of Mr. Khashoggi, who was working as a columnist for The Washington Post while living in the United States, and a United Nations investigator recently pointed the finger at Prince Mohammed as well.

Climate change is still a core dispute.

Climate change stood out as a clear area of contention among the world leaders coming into the G20 summit in Osaka. Mr. Trump has signaled that the United States will withdraw from the Paris climate accord, while President Emmanuel Macron of France threatened this past week that he would not sign any joint statement unless it dealt with climate change, which he called a “red line.”

In a clear move to prevent the group from splintering, the final statement that leaders agreed to at the summit’s conclusion on Saturday reflected an agree-to-disagree approach. The statement said that those signatories that had confirmed their commitment to the pact at the G20 summit in Buenos Aires last year “reaffirm their commitment to its full implementation.”

But the statement also declared that the United States reiterated “its decision to withdraw from the Paris Agreement because it disadvantages American workers and taxpayers.”

Prime Minister Shinzo of Abe of Japan, the host of the meeting, acknowledged after the end of the final general session that there had been “major differences in opinions” on climate change. “But to hand over a better planet to the next generation is shared by everyone,” Mr. Abe said, adding, “I believe what is important is to deliver outcomes.”

Climate activists expressed disappointment that the G20 had not been able to push for more aggressive targets.

Trump was distracted by politics at home.

Even from 7,000 miles away, Mr. Trump kept close tabs on his 2020 Democratic rivals.

The president demonstrated a close familiarity with a dramatic exchange on Thursday between Senator Kamala Harris of California and former Vice President Joseph R. Biden Jr. Ms. Harris drew favorable reviews, particularly on the left, for her stinging attack on Mr. Biden’s history of opposing school integration through busing and his warm recollections of his work with segregationist senators.

Mr. Trump said he was less impressed: “I thought that she was given too much credit,” he said. “It wasn’t that outstanding.”

Mr. Trump also lashed out at a former president, Jimmy Carter, who had questioned the legitimacy of Mr. Trump’s 2016 victory by saying he had “no doubt” that Russia had meddled in the presidential election.

“He’s a nice man. He was a terrible president,” Mr. Trump said in response to a question during a news conference. He added: “I won not because of Russia, not because of anybody but myself.”