But he appeared to acknowledge that not all of the outstanding issues were likely to be resolved by negotiators and that he and President Xi Jinping of China might need to be involved before a final agreement is reached.

“At some point, I expect to meet with Xi,” Mr. Trump said, noting that the two leaders could potentially “make the parts of the deal that the group is unable to make.”

The American negotiators will probably get a frosty greeting in Beijing.

Already, a stopgap deal reached by Mr. Trump and Mr. Xi on Dec. 1 in Buenos Aires has proved to be unpopular within the Chinese government, people with detailed knowledge of Chinese economic policy deliberations said. The agreement essentially allowed Mr. Trump to maintain tariffs he had ordered on Chinese goods while China stepped back from many of its retaliatory moves.

The internal displeasure in Beijing may be contributing to the lack of progress in trade talks since then. United States trade officials noted at a White House briefing on Jan. 31 that negotiators had not produced a draft framework of what a final agreement might look like.

Still, given the Chinese government’s track record for failing to keep its trade promises, American negotiators feel that any deal must have some sort of mechanism that will swiftly inflict higher tariffs on China if it does not comply.

The mechanism they have in mind is one Beijing has fought vociferously in the past.

When China joined the World Trade Organization in 2001, the international body approved a rule that allowed member countries to raise tariffs if increases in Chinese exports disrupted their domestic markets. Many countries were loath to use it, given China’s growing economic might.