African countries are innocent victims of the war in Ukraine and Russia should help ease their suffering, the head of the African Union has told Vladimir Putin at a meeting in Russia.
After talks in Sochi, Macky Sall said the Russian leader had promised to ease the export of cereals and fertiliser, but gave no details.
Mr Putin denied Moscow was preventing Ukrainian ports from exporting grain.
Over 40% of wheat consumed in Africa usually comes from Russia and Ukraine.
But Ukraine's ports in the Black Sea have been largely blocked for exports since the conflict began. Kyiv and its allies blame Moscow for blockading the ports, which Ukraine has mined to prevent a Russian amphibious assault.
"Failure to open those ports will result in famine," the UN's crisis coordinator Amin Awad said in Geneva.
He said a grain shortage could affect 1.4 billion people and trigger mass migration.
The war has exacerbated already existing shortages in Africa caused by bad harvests and insecurity.
Food prices have shot up across the continent since Russia invaded Ukraine 100 days ago, pushing huge numbers towards hunger.
The head of the World Food Programme, Mike Dunford, said more than 80 million people were acutely food insecure, acutely hungry in Africa - up from about 50 million people this time last year.