President Trump told the leader of Turkey that he has instructed U.S. generals to stop supplying arms to Kurdish fighters in Syria, according to Turkey's foreign minister.Turkey's foreign minister, Mevlut Cavusoglu, spoke with reporters Friday following a phone call between Trump and Turkish President Recep Tayyip Erdogan.In a statement about the call, the White House did not confirm Cavusoglu's remarks about the Kurds, but it could have been alluding to a shift when it said:"Consistent with our previous policy, President Trump also informed President Erdogan of pending adjustments to the military support provided to our partners on the ground in Syria, now that the battle of Raqqa is complete and we are progressing into a stabilization phase to ensure that ISIS cannot return."The Associated Press reports that the announcement appeared to catch the U.S. State Department and Pentagon off-guard. The Kurds have been invaluable partners to the U.S. in the fight against ISIS, and stopping the supply of arms to those fighters would represent a big policy change.As NPR's Peter Kenyon reports from Istanbul, the Turkish government considers Kurdish fighters close allies with the militant PKK, which has been fighting in Turkey for more than three decades. Both the U.S. and Turkey consider the PKK a terrorist group.As recently as May, the Trump administration was refusing to stop arming the Kurds. As Kenyon reported at the time: