News of a broad U.S. investigation of Huawei Technologies Co. over possible Iran sanctions violations adds to the tension over trade as senior U.S. officials head to China in the coming days in hopes of a deal.

President Donald Trump is dispatching his top economic and trade advisers -- Larry Kudlow, Robert Lighthizer and Peter Navarro -- to join Treasury Secretary Steven Mnuchin on a visit to China, two people familiar with the matter said.