SINGAPORE—After the U.S. and China reached an agreement this past week to end the latest skirmish in their trade war, President Trump wrote on social media that he and Xi Jinping will “work closely together to open up China to American Trade.

If a handshake agreement holds, it will merely undo some of the damage from the trade war that President Trump started.

China on Thursday affirmed a trade deal announced by U.S. President Donald Trump, saying both sides needed to abide by the consensus and adding China always kept its word. The deal, reached after Trump and China's President Xi Jinping spoke on the telephone last week,