WASHINGTON — President Trump this week will turn his attention from a fight with congressional Democrats to an even more formidable negotiating challenge, one with potentially higher stakes: China.

Trade talks with Beijing begin on Wednesday in Washington, kicking off a monthlong sprint of negotiations between the two nations that could prove more difficult than Mr. Trump’s unsuccessful attempt to secure money from Congress for a border wall.

The negotiations come at a critical moment for Mr. Trump’s economic agenda and the global economy, which is beginning to slow in part because of the president’s trade policies.

This week, a Chinese delegation led by Liu He, the vice premier, will meet with an American delegation led by Robert Lighthizer, Mr. Trump’s top trade negotiator, and Steven Mnuchin, the Treasury secretary. A White House official said on Monday that Mr. Liu will meet personally with Mr. Trump on Thursday.