"The termination of the Black Sea grain deal will have a series of consequences, ranging from the increase in global food prices to scarcity in certain regions and, potentially, leading to new waves of migration," Erdogan told reporters on a flight returning from a trip to Gulf countries and northern Cyprus.

"I believe that by thoroughly discussing the matter with President Putin, we can ensure the continuation of this humanitarian effort," Erdogan added.

Russia this week quit a deal - brokered by the United Nations and Turkey - that allowed the safe Black Sea export of Ukraine grain for the past year, and revoked guarantees of safe navigation. Since then, no ships have sailed from Ukrainian ports.

Moscow says it will return to the deal only if its demands are met for easier access for its own food and fertiliser exports to world markets. Western countries say Russia has had no trouble selling food, which is exempt from financial sanctions.

"We are aware that President Putin also has certain expectations from Western countries, and it is crucial for these countries to take action in this regard," Erdogan said.

Russia pounded Ukrainian food export facilities for a fourth day in a row on Friday and practised seizing ships in the Black Sea in an escalation of what Western leaders say is an attempt to wriggle out of sanctions by threatening a global food crisis.

Erdogan repeated earlier remarks that he hoped Putin would visit Turkey in August.

"I believe that, without prolonging the process, we will ensure the continuation of the Black Sea grain initiative.