His statement took specific aim at John R. Bolton, Mr. Trump’s national security adviser, who had said on a Sunday television show that North Korea needed to dispose of its nuclear weapons program quickly, following what he called the model of Libya under Col. Muammar el-Qaddafi.
Chinese analysts say North Korea’s elite see Libya, and Mr. Qaddafi’s inability to subsequently defend himself when Western powers backed the popular uprising that toppled him, as a warning not to give up nuclear weapons. They said it was Mr. Bolton’s impolitic comments, and not behind-the-scenes Chinese machinations, that hardened North Korean attitudes.
“Subverting the summit would bring even bigger uncertainties to China,” said Shi Yinhong, professor of international relations at Renmin University in Beijing.
Mr. Shi said China would benefit from easing tensions on the peninsula, with a lifting of sanctions allowing a resumption of trade along its shared border with the North. In fact, he said Mr. Xi probably used the Dalian meeting to entice Mr. Kim with expanded economic ties to help Mr. Kim fulfill his promise to his own people to fix the North’s dilapidated economy.
Mr. Trump himself has often linked North Korea and trade, telling the Chinese that he would give them a better deal on the latter if they cooperated on North Korea, said Bonnie Glaser, a China expert at the Center for Strategic and International Studies in Washington.
Some analysts said this was apparent in the Trump administration’s handling of ZTE, the Chinese telecommunications equipment company that the United States barred from buying American-made parts as punishment for its dealings with North Korea and Iran, threatening the company’s survival.
The United States eased off that punishment after Mr. Trump said on social media that he was working with Mr. Xi to give ZTE “a way to get back into business, fast.”