WASHINGTON - US President Donald Trump will speak by phone soon with Turkish President Tayyip Erdogan to raise US concerns about Turkey's offensive against Kurdish forces in northwest Syria, a senior administration official said on Tuesday.The official, who briefed reporters on condition of anonymity, said Turkish officials have sent "conflicting signals" about the scope of the offensive against the U.S.-backed Kurdish YPG in Syria’s Afrin region."We're going to have to see how this develops on the ground. But our message has been unified. We would appreciate it and we would urge them to limit the incursion as much as possible," the official said.The official said the call would take place soon. A separate official said Trump planned to speak with Erodgan on Wednesday.