MOSCOW, Oct 29 (AFP) - Russia on Saturday (Oct 29) suspended its participation in a landmark agreement that allowed vital grain exports from Ukraine, blaming drone attacks on Russian ships in Crimea.

Russia made the announcement after its army accused Kyiv earlier Saturday of a "massive" drone attack on its Black Sea fleet, which Ukraine labelled a "false pretext" and the UN urged the deal's preservation.

The Turkey and UN-brokered deal to unlock grain exports signed between Russia and Ukraine in July is critical to easing the global food crisis caused by the conflict.

The agreement already allowed more than nine million tonnes of Ukrainian grain to be exported and was due to be renewed on Nov 19.

A Turkish security source told AFP that Ankara had not been "officially notified" of Russia's suspension, while Ukraine and the UN pushed for the agreement to remain in force.

"I call on all states to demand that Russia stop its hunger games and recommit to fulfilling its obligations," Ukrainian Foreign Minister Dmytro Kuleba said on Twitter.

Stephane Dujarric, spokesman for the UN secretary-general, said: "It is vital that all parties refrain from any action that would imperil the Black Sea Grain Initiative which is a critical humanitarian effort."

Ukrainian President Volodymyr Zelenskyy said that the suspension of the deal requires a strong international response from the United Nations and the Group of 20 major economies.

In a video address, he accused Russia of trying to create an artificial famine in Africa, the Middle East and South Asia.