Turkey is stepping up efforts to salvage a critical deal to export Ukrainian grains after Russia announced it was suspending its participation over alleged Ukrainian attacks on occupied Crimea. In a phone call today, Russia’s President Vladimir Putin told his Turkish counterpart Recep Tayyip Erdogan that Moscow could resume the deal if it has “real guarantees” from Kyiv.

Turkish Foreign Minister Mevlut Cavusoglu had spoken to his Russian counterpart Sergey Lavrov Monday to discuss conditions under which Russia would resume its role in the deal. The agreement brokered in July by Ankara and the United Nations allowed Ukraine, the world’s top supplier of grains alongside Russia, to resume exports amid mounting fears of a global food crisis.

Turkey's Defense Minister Hulusi Akar held a separate call with Russia’s defense chief, Sergei Shoigu, urging the Kremlin to reconsider its stance. Akar called the deal “a purely humanitarian effort” and said it should be set apart from the ongoing war between Russia and Ukraine.

Erdogan has vowed to keep the deal alive. “Even if Russia behaves hesitantly because it didn't receive the same benefits, we will decisively continue our efforts to serve humanity," Erdogan said in a speech Monday.