Turkey urged the United States on Thursday to halt its support for Kurdish YPG fighters or risk confronting Turkish forces on the ground in Syria, some of Ankara¡¯s strongest comments yet about a potential clash with its NATO ally.

The remarks, from the spokesman for President Recep Tayyip Erdogan¡¯s government, underscore the growing bilateral tensions, six days after Turkey launched its air and ground operation, ¡°Olive Branch,¡± in Syria¡¯s northwestern Afrin region.

In Washington, the Pentagon said that it carefully tracked weapons provided to the YPG and would continue discussions with Turkey.