Turkey's Foreign Minister Mevlut Cavusoglu said on Monday that a German parliamentary delegation could visit a NATO base in Konya but suggested it was not yet possible for them to go to the Incirlik base in southern Turkey.

"At the moment a visit to the NATO base in Konya is possible, rather than Incirlik," Cavusoglu told a news conference after talks in Ankara with his German counterpart Sigmar Gabriel.

Ties between the NATO allies deteriorated sharply in the run-up to Turkey's April 16 referendum that handed President Tayyip Erdogan stronger presidential powers.

Turkey has prevented German lawmakers from visiting the roughly 250 troops stationed at Incirlik as part of the U.S.-led coalition against Islamic State, saying that Berlin needs to improve its attitude first.