Turkish Prime Minister Binali Yildirim (C) walks at the scene of Tuesday's car bomb attack on a police bus, in Istanbul, Turkey, June 8, 2016. REUTERS/Osman Orsal

ANKARA (Reuters) - Turkey will not allow cooperation with terrorist organizations in Syria even as it supports the U.S.-led coalition against Islamic State, Prime Minister Binali Yildirim said on Tuesday.

Ankara and Washington have long been at loggerheads over the role of a U.S.-backed Syrian Kurdish militia. Turkey says the fighters are terrorist organization affiliated with the outlawed Kurdistan Workers Party (PKK). The U.S. sees the Syrian Kurdish fighters as a key partner in the battle against Islamic State.

Yildirim made the comment in a speech to his ruling AK Party in parliament that was broadcast live on television.