Flags promoting the upcoming second Russia-Africa summit are pictured in Saint Petersburg on Tuesday. AFP

The Russian president will on Thursday host leaders of African countries for a summit in his native Saint Petersburg, as the continent braces for the consequences of Moscow's withdrawal from the Ukraine grain export deal.

Isolated on the international scene since launching a full-scale military intervention in Ukraine, Vladimir Putin still has support in several African countries.

"It is important that in recent years our cooperation with Africa has reached a new level. We intend to further develop it," Putin said in a welcome letter to participants of the summit.

Seventeen African leaders including South African President Cyril Ramaphosa are expected at the Russia-Africa summit set to take place on Thursday and Friday.

The Kremlin has accused Western countries of trying to prevent African states from participating in the summit.

The summit is the second of its kind after an inaugural one held in 2019 in Sochi, southern Russia.

Putin is expected to conduct bilateral talks with his counterparts on the sidelines and will deliver an address at the plenary session.

Vladimir Putin shakes hands with Ethiopian Prime Minister Abiy Ahmed during a meeting. Reuters

In the speech he will discuss his vision of Russia-Africa ties and the "formation of a new world order", according to Kremlin foreign policy adviser Yuri Ushakov.

The end of a deal that has allowed Ukrainian grain exports through the Black Sea to global markets, including Africa, is expected to dominate the agenda.

Over a year, the deal allowed around 33 million tonnes of grain to leave Ukrainian ports, helping to stabilise global food prices and avert shortages.

US Secretary of State Antony Blinken pressed African leaders attending the summit to demand answers about the grain disruptions that have propelled poorer nations towards crisis.

"They know exactly who's to blame for this current situation," Blinken said of the leaders.

"My expectation would be that Russia will hear this clearly from our African partners," he said Thursday during a visit to New Zealand.

Agence France-Presse