NATO member Turkey has delivered combat drones to Ukraine and sought to act as mediator in the conflict, but has refrained from slapping sanctions on Russia on which it relies for grain and energy.
Ankara has also offered, at the request of the United Nations, to help secure maritime corridors for the export of Ukrainian grain.
Russian Foreign Minister Sergei Lavrov will be in Turkey on Wednesday to discuss the issue.
Food prices have soared since the war began, with countries in Africa and the Middle East particularly at risk since grain cannot be delivered because of the Russian navy blockade of Ukrainian ports in the Black Sea.