G7 industrialised nations on Tuesday urged countries and companies with large food stockpiles to help ease a hunger crisis sparked by Russia's invasion of Ukraine.

"We call on those partners with large food stockpiles, as well as on the private sector, to make food available without distorting the market," the Group of Seven leaders said in a statement after a summit in Germany.

They called "on all countries to avoid excessive stockpiling of food which can lead to further price increases".

The war in Ukraine, a country known as Europe's breadbasket, has pushed up food prices and led to shortages, as Russia's blockade of Black Sea ports prevents millions of tonnes of grain from being shipped out.

The crisis has sparked fears of famine in vulnerable countries highly reliant on Ukrainian exports, particularly in Africa.

The issue was a key topic of discussion at a three-day summit of the G7 -- comprising Britain, Canada, France, Germany, Italy, Japan and the United States -- held in the Bavarian Alps.

In their final communique, G7 leaders pledged an additional $4.5 billion to combat global food insecurity, bringing the total sum committed this year to more than $14 billion.

They again urged Russia to "end its blockade of Ukrainian Black Sea ports, destruction of key port and transport infrastructure, grain silos and terminals, illegal appropriation by Russia of agricultural commodities and equipment in Ukraine".

These actions "can only be assessed as a geopolitically motivated attack on global food security", they said.

Russia denies being responsible for the food crisis and blames the delivery disruptions on Western sanctions.