Israeli and Palestinian leaders are set to address the United Nations General Assembly on Thursday, a day after President Trump said he hoped to engineer the framework for a peace deal in the coming months.

President Nicolás Maduro of Venezuela is also to take the lectern to address the General Assembly.

Earlier this week, Mr. Trump largely overshadowed the other heads of state who gathered for the 73rd assembly, first drawing laughter from a roomful of foreign leaders and then surprising many when he accused China of interfering in the midterm elections.

During his opening remarks at the Security Council on Wednesday morning, Mr. Trump accused China of trying to meddle in the United States’ elections, set for November.

“Regrettably, we found that China is attempting to interfere in our upcoming 2018 election, coming up in November, against my administration,” Mr. Trump said. “They do not want me, or us, to win, because I am the first president ever to challenge China on trade. And we are winning on trade, we are winning at every level.”

Mr. Trump provided no evidence to back up his assertion, although he was apparently referring to retaliatory tariffs from China in the escalating trade war. Later in the day, during an evening news conference, he said that “we have evidence” of China’s interference.

“I like China and I like President Xi a lot,” Mr. Trump said, but later added, “They’re trying to convince people to go against Trump.”

Much of his speech on Wednesday at the Security Council was devoted to criticizing Iran, a theme that dominated his address to the General Assembly a day earlier.

“The regime is the world’s leading sponsor of terror and fuels conflict across the region and beyond,” Mr. Trump said, before calling the Iran nuclear deal a “horrible, one-sided” agreement.

“They were in big, big trouble,” before the 2015 nuclear accord that led to the lifting of sanctions, he said of Iran. “They needed cash; we gave it to them.”

He said he planned to introduce new economic sanctions on Iran this year, adding that they would be “tougher than ever before.”

Yet Mr. Trump also had positive words for Iran, thanking its leadership and Russia for delaying a planned offensive on Idlib Province in Syria, where government forces are believed to be preparing what would most likely be the final military blow against rebels and their civilian supporters.

President Emmanuel Macron of France, who spoke to the Security Council directly after Mr. Trump, urged unity within the group. He said that relations with Iran must not be limited to a “policy of sanctions” and that long-term strategies must be put in place.

The 15-member Security Council is the most powerful arm of the United Nations, with the ability to impose sanctions and authorize military intervention. — MEGAN SPECIA and TESS FELDER

Mr. Trump confirmed at a news conference that he had rejected a one-on-one meeting with Prime Minister Justin Trudeau of Canada, and he denounced the country over its approach to trade.

“Frankly, we are thinking about just taxing cars that are coming in from Canada,” Mr. Trump said. “We are very unhappy with the negotiations — with the negotiating style — of Canada.”

He went on to criticize Canada, and specifically called out its negotiators, over the Nafta trade deal — an agreement he called “very bad for the U.S.” — and the recent tariffs put in place on American-made products.

“Canada has treated us very badly, they have treated our farmers in Wisconsin and New York State very badly,” he said. “So Canada has a long way to go, I must be honest with you, we are not getting along with their negotiators at all.”

While he did not rule out the prospect of a new trade deal with Canada, he said it would probably be very different from what the Canadians are seeking. — MEGAN SPECIA

As the world’s oldest leader at age 93, Prime Minister Mahathir Mohamad of Malaysia has seen a lot of politicians come and go — including himself: He served as prime minister from 1982 to 2003, and returned to power in May.

He has also stood up to his regional powerhouse, diplomatically pushing back on financially onerous Chinese projects in Malaysia.

While visiting New York for the General Assembly this week, he offered some cautionary advice for President Trump: Don’t push too hard, he said in discussing Mr. Trump’s comments about the Chinese government.

“I get the impression he doesn’t know much about Asia,” the Malaysian leader said at a meeting of the Council on Foreign Relations.

Asked whether he thought a rapidly modernizing China was engaged in a new colonialism, Mr. Mahathir answered indirectly, “When China is poor, it is dangerous,” he said. “When China is rich, it also is dangerous.”

While Mr. Trump has sought to cast China as a villain in his campaign to “make America great again,” Mr. Mahathir suggested that more subtlety was required.

“We have been dealing with China for 2,000 years,” he said. “I think you can make America great in many other ways.” — RICK GLADSTONE

President Hassan Rouhani of Iran, apparently emboldened by the less-than-enthusiastic reception for President Trump, said the United States had isolated itself by renouncing the Iranian nuclear agreement and by warning others they a failure to heed restored American sanctions could bring reprisals.

At a news conference near the end of his annual visit to the General Assembly, Mr. Rouhani thanked the many other member states, including close American allies, that have expressed support for the nuclear accord. The United States withdrew from the agreement in May on Mr. Trump’s orders.

Mr. Trump, the Iranian president said, ordered other countries not only to ignore the nuclear accord but also to essentially disregard Security Council Resolution 2231, which put it into effect. Security Council resolutions are supposed to be regarded as having the force of law.

“It is quite strange, asking other members not to adhere to 2231,” Mr. Rouhani told reporters. Asked if Iran felt isolated and surrounded by hostile powers in the Middle East, Mr. Rouhani responded: “We’re not isolated. America is isolated.”

While he acknowledged that United States sanctions had put pressure on his country, Mr. Rouhani said, “Iran has been in much tougher positions.” And even as he thanked European countries for abiding by the nuclear agreement, he would not rule out the possibility that Iran itself might also abandon the accord if it does not get the promised economic benefits. — RICK GLADSTONE