The U.S. provided military training and supplied truckloads of weapons to the YPG, disregarding warnings from Ankara that the YPG is organically linked to the PKK, and partnering with one terrorist group to fight another was not acceptable.
After days of conflicting statements about a timeline for U.S. President Donald Trump's decision to pull out American troops from Syria, a U.S. defense official said Friday the withdrawal process has begun with some military cargo pulled out.
Trump's decision to withdraw all of the 2,000 U.S. troops from the war-torn country prompted shockwaves among USA senior officials and United States allies in December.
"We are not withdrawing troops at this stage", the official said on condition of anonymity.
Officials have previously told CNN to expect to see discussion of percentages of equipment withdrawn as a way of meeting Trump's intent - even though it's expected that no troops are coming out immediately.
Also citing unnamed Pentagon officials, NYT corrected its Syria withdrawal report Friday, from suggesting US troops had begun leaving to acknowledging that only "planning has begun".
The Syrian Observatory for Human Rights reported that the coalition had started scaling down its presence at Rmeilan airfield in the Hasakah province in northeastern Syria.
US Secretary of State Mike Pompeo, who has been touring the Middle East this week to reassure allies of Washington's commitment to regional security, said on Saturday he was "optimistic" a way could be found to protect Syrian Kurds while allowing Turks to defend their country despite a US pullout from Syria.
On the same day, however, Mr Pompeo said in a speech that "when America retreats, chaos often follows".
Turkish President Recep Tayyip Erdogan labelled Mr Bolton's comments unacceptable and a "grave mistake".
Turkey considers the YPG a terrorist movement and has repeatedly threatened to move into Syria to create a buffer zone along the border. The withdrawal benefits Syrian President Bashar Assad and his global backers, Russian Federation and Iran, who are primed to move into the region to fill a vacuum left behind by the Americans.
Democratic Congressman Adam Schiff, who chairs the House Intelligence Committee, blasted the withdrawal plans.
Though Mr Trump has said he wants a withdrawal to be coordinated, gradual and "prudent", observers have stressed that his announcement was having the same impact as a withdrawal itself.
"On the ground, the announcement of the pullout is as if they were already gone".