Turkey has offered to guard and run Kabul’s airport after the United States and other NATO forces withdraw from Afghanistan, but US officials say Ankara is imposing conditions that need to be resolved as their leaders prepare to meet next week.

Axar.az reports citing foreign media that Turkish officials say Ankara made the proposal at a NATO meeting in May when the United States and its partners agreed on a plan to withdraw troops by Sept. 11 after 20 years of war trying to defeat Taliban forces.

Turkish Defence Minister Hulusi Akar said on Monday that Ankara’s offer was contingent on backup from those allies.