Syria's Kurds battled to hold off a Turkish invasion on Thursday as thousands of civilians fled air strikes and shelling that deepened fears of a humanitarian crisis.
US President Donald Trump tried to justify the de facto green light he gave his Turkish counterpart Recep Tayyip Erdogan for an assault seen as a blatant betrayal of Washington's erstwhile Kurdish allies.
Later Trump suggested that Washington could mediate between Turkey and Kurdish groups and a US official said Trump has asked American diplomats to broker a ceasefire.