Britain will host a global food security summit in November to support countries dealing with the impact of Russia's Black Sea grain blockade, Prime Minister Rishi Sunak will announce on Friday at the G20 summit in India.

Sunak will say global leaders must make it clear that Russian President Vladimir Putin's withdrawal from the Black Sea Grain Initiative has increased Russia's global isolation, Sunak's office said.

The deal, agreed in the aftermath of Russia's invasion of Ukraine, allowed major food grain producer Ukraine to safely export grain via the Black Sea, but it expired in July, increasing global food prices.

"Once again, Vladimir Putin is failing to show his face at the G20 ... the rest of the G20, meanwhile, are demonstrating that we will turn up and work together to pick up the pieces of Putin's destruction," Sunak said in a statement as he departed for New Delhi.

"That starts with dealing with the terrible global consequences of Putin's stranglehold over the most fundamental resources, including his blockade of and attacks on Ukrainian grain."

The food security summit, which will take place in London on Nov. 20, will bring together governments, international organisations and companies to tackle the causes of food insecurity and malnutrition, Sunak's office said.

Britain will also use military intelligence and surveillance to monitor Russian activity in the Black Sea to deter any Russian strikes against civilian vessels transporting grain, it added. (Reporting by Sachin Ravikumar; Editing by Sandra Maler)