A potential Black Sea corridor to export grain from Ukraine tops the meeting agenda in Istanbul. However, the UN chief says there is "still a way to go" to clinch a deal.
Turkey will host Russian and Ukrainian delegations with UN diplomats on Wednesday to try and free up grain exports through the Black Sea.
"Military delegations from Turkey, Russia and Ukraine and a United Nations delegation will be conducting talks in Istanbul tomorrow regarding safe transfer of grain waiting in Ukrainian ports to international markets via sea route," Turkish Defense Minister Hulusi Akar said on Tuesday.
The plans set to be discussed include having Ukrainian vessels guide grain ships around sea mines, Russia agreeing to a truce while shipments move, and Turkey inspecting ships with UN support in order to ally Russian fears of potential weapons smuggling.
Ukraine, one of the world's largest grain suppliers, has struggled to ship grain because of Russia's invasion. Kyiv also accuses Moscow of blocking, and sometimes stealing, its grain.
It usually exports 6 million to 7 million tons of grain per month. Last month, however, the "breadbasket of the world," as Ukraine is frequently referred to, shipped out only 2.2 million tons, according to the Ukrainian Grain Association.