US President Donald Trump is urging his Turkish counterpart Recep Tayyip Erdogan to curtail the country's military operation in northern Syria. In a phone call on Wednesday, Trump warned Erdogan that the continued offensive might lead to conflict between American and Turkish forces. President Erdogan replied that the US must stop weapons support to the Syrian Kurdish militia. Intense air raids and shelling in the Syrian region of Afrin started on Saturday against the US-backed YPG fighters. The Turkish government considers the YPG a terrorist group affiliated with the Kurdish Workers' Party. Turkey also plans to extend its operations to Manbij, east of Afrin.