Russia has pointed the finger at actions by the West for grain exports from Ukraine being blocked.
The blockade, combined with the shortage of overland shipping routes, means that significant supplies of grain remain in storage and cannot be exported from Ukraine.
Kremlin spokesperson Dmitry Peskov said: “We categorically do not accept these accusations. On the contrary, we blame Western countries of taking actions that have led to this.”
Foreign Secretary Liz Truss has accused Vladimir Putin of seeking to “hold the world to ransom” through Russia‘s blockade of Ukrainian grain exports.
During a visit to Bosnia, she said: “It is completely appalling that Putin is trying to hold the world to ransom, and he is essentially weaponising hunger and lack of food amongst the poorest people around the world.
“We simply cannot allow this to happen. Putin needs to remove the blockade on Ukrainian grain.
“What we cannot have is any lifting of sanctions, any appeasement, which will simply make Putin stronger in the longer term.”
British military authorities say Ukraine’s overland export routes are “highly unlikely” to offset the problems caused by Russia’s blockade of the Black Sea port of Odesa, putting further pressure on global grain prices.
Russia and Ukraine account for nearly a third of global wheat supplies and the lack of exports from Ukraine is contributing to a growing global food crisis.
Turkey is in talks with Russia and Ukraine to open a corridor via the Bosphorus for grain exports from Ukraine, according to a senior Turkish official.
The official said: “Turkey is negotiating with both Russia and Ukraine for the export of grains from Ukraine.
“With a corridor to be opened from Turkey, there was a demand for this grain to reach their targeted markets. Negotiations are still ongoing.”
The UN have been attempting to forge a deal to resume Ukrainian food exports and Russian food and fertiliser exports.
However, the difficulties include Russian demands for sanctions to be lifted in return and the cost of insuring the maritime route.