Russian President Vladimir Putin on Tuesday said that the West must remove restrictions on exports of Russian grain.

"We will facilitate the export of Ukrainian grain, but we are proceeding from the fact that all restrictions related to possible deliveries for the export of Russian grain will be lifted," Putin told reporters in Tehran after talks with the presidents of Iran and Turkey.

Russia's military intervention in Ukraine has hampered shipments from one of the world's biggest exporters of wheat and other grain, sparking fears of global food shortages.

"As you know, Americans have lifted -- essentially lifted -- restrictions on the supply of Russian fertilizers to the world markets," Putin said. 

"If they sincerely want to improve the situation on the international food markets, I hope the same will happen with the supply of Russian grain for export."

Cereal prices in Africa, the world's poorest continent, have surged because of the slump in exports from Ukraine, sharpening the impact of conflict and climate change and sparking fears of social unrest.

The United Nations has said Africa faces an "unprecedented" crisis caused by the conflict.