Turkey has closed its airspace to Russian civilian and military planes flying to Syria, Foreign Minister Mevlut Cavusoglu has been quoted as saying by local media.

“We closed the airspace to Russia’s military planes – and even civilian ones – flying to Syria. They had until April, and we asked in March,” Turkish media quoted Cavusoglu as saying on Saturday.

Cavusoglu said he conveyed the decision to his Russian counterpart Sergey Lavrov, who then relayed it to President Vladimir Putin.

“One or two days later, they said: Putin has issued an order, we will not fly any more,” Cavusoglu was quoted as telling Turkish reporters on board his plane to Uruguay.

Cavusoglu added that the ban would stay in place for three months.

There was no immediate response to Turkey’s announcement from Russia, which together with Iran has been a crucial supporter of Syrian President Bashar al-Assad during the war in the country.

Turkey has backed Syrian rebels during the conflict.

Ankara’s relations with Moscow briefly imploded after Turkey shot down a Russian warplane near the Turkish-Syrian border in 2015.

However, they had been improving until Russia’s invasion of Ukraine, which Turkey views as an important trade partner and diplomatic ally.

Turkey has been trying to mediate an end to the conflict, hosting meetings between Russian and Ukrainian negotiators in Istanbul, and another between Lavrov and Ukrainian counterpart Dmytro Kuleba in Antalya.

Ankara is now trying to arrange an Istanbul summit between Putin and Ukrainian President Volodymyr Zelenskyy, although Cavusoglu conceded that the prospects of such talks at this point remain dim.

“If they want a deal, it’s inevitable,” Cavusoglu was quoted as saying. “It might not happen for a long time, but it can happen suddenly.”