Russia and Ukraine have made enough progress on resolving their dispute over blocked grain exports to hold new talks in Turkey next week, the Turkish defence minister said Wednesday.

"It was agreed that the Russian and Ukrainian delegations should meet again in Turkey next week," Hulusi Akar said in a statement after the first talks in Istanbul between Russian and Ukrainian delegations since March.

Akar said the two countries' defence delegations agreed on "joint controls" at ports and on ways to "ensure the safety of the transfer routes" across the Black Sea.

He signalled that a final agreement on releasing an estimated 20 to 25 million tonnes of grain now blocked in Ukrainian ports could be announced next week.

"At this meeting, which we will hold next week, all the details will be reviewed once again and the work we have done will be signed," Akar said.