The stakes of the trip are high after months of increasing strain between China and the United States. Fears about a trade war between the world’s two biggest economic powers emerged in March after Mr. Trump unveiled tariffs on global imports of aluminum and steel. The threat of tariffs on up to $150 billion of Chinese imports followed.

Next month, the Treasury Department is expected to release a plan to further restrict Chinese investment in American companies, including industries such as semiconductors and artificial intelligence that are sensitive for national security reasons. The rules could also restrict American partnerships with Chinese companies abroad.

China has not taken such threats lightly. In recent weeks it has hit back with its own threats, raising concerns among farmers and businesses in the United States that the escalating dispute could be a drag on the economy and blunt the effect of the tax cuts Mr. Trump signed into law in December.

But Mr. Xi has also signaled that he is open to negotiating with Mr. Trump. He said this month that China would reduce its tariffs on autos, which Mr. Mnuchin called “a big step in the right direction.”

While some trade experts warned that China has failed to deliver on such promises before, Mr. Trump insisted on Tuesday that he was encouraged about the possibility of a deal.

“President Xi made a speech four days ago where he said that China is going to be opened up,” Mr. Trump said. “Because it’s not opened up right now. They trade with us. We can’t trade with them.”

Some China analysts were not so impressed by Mr. Xi’s speech. “I thought it was a bunch of warmed-over repetition of things we had heard before,” said Scott Kennedy, a China analyst at the Center for Strategic and International Studies. “For me, the concern is that the level of mixed messaging that we’re sending the Chinese makes them expect that they can get through this with a very limited offer.”