US President Joe Biden and his Turkish counterpart Recep Tayyip Erdogan failed to find a solution to the dispute concerning Ankara's purchase of Russian S-400 missile systems, US National Security Advisor Jake Sullivan said.
He added, however, that there's a commitment to continue the dialogue on the matter.
Previously, the Turkish president said he made it clear to Biden that Ankara's position on its S-400 missile systems remains unchanged.
The two presidents agreed that Turkey will take the leading role in securing Kabul Airport as the US and NATO withdraw their forces from Afghanistan.
According to Sullivan, the US administration will also consider a backup plan in case Turkey can't proceed with its role or proceeds not in accordance with the original agreement.