The foreign ministers of Russia and Turkey spoke by telephone on Sunday, a day after Ankara angered Moscow by sending five Ukrainian commanders home with President Volodymyr Zelenskiy in what Russia called a violation of a prisoner exchange agreement.

The Russian and Turkish foreign ministries said Sergei Lavrov and Hakan Fidan discussed the situation in Ukraine, as well as a Black Sea grain export agreement that lifted a Russian de facto blockade of Ukrainian ports last year.

Moscow has threatened to quit the grain export deal when it comes up for renewal on July 17, saying demands to facilitate sales of its own grain and fertiliser have not been met.

Turkey’s President Tayyip Erdogan said on Saturday that he was pressing Russia to extend the deal, brokered last year by Ankara and the United Nations, by at least three months.