U.S. and China negotiators have agreed on “a lot of the most difficult points” in efforts to restore normal trade between the two countries,  President Donald Trump said last week before a meeting with Chinese Vice Premier Liu He.

Trump said he would hold a summit with China President Xi Jinping if the two sides can agree to a deal, which he said could happen within the next four weeks. President Xi also touted substantial progress in trade talks, according to the Chinese state...