Apparently, the US had "depicted" Kurdish militias in northern Iraq and reported its findings to the Turks

They are combating - at once - the Mahdi Army of Shi'ite cleric Muqtada al-Sadr, former Ba'athists loyal to ex-president Saddam Hussein, and al-Qaeda. And to say the least, the US is winning none of these wars. It simply cannot open another front in the relatively stable district of northern Iraq. That is why it has turned a blind eye to PKK activity in Iraqi Kurdistan, enabling the military group to set up bases, recruit people and purchase arms for cross-border operations into Turkey.