United Nations Secretary-General Antonio Guterres said on Tuesday that "there is still a way to go" in talks to try and resume Ukraine Black Sea exports of grain.
"We are working hard indeed, but there is still a way to go," Guterres told reporters. "Many people are talking about it, we prefer to try and do it."
NATO member Turkey has been spearheading efforts to resume the grain deliveries, and to that end, will host a meeting to try to get grain and other foodstuffs to a hungry world - especially Africa.
Turkish officials say they have 20 merchant ships waiting in the Black Sea that could be loaded quickly with Ukrainian grain.
Turkish Defense Minister Hulusi Akar announced the meeting in a statement on Tuesday, but did not specify who will represent each side.
"Military delegations from the Turkish, Russian and Ukrainian defense ministries, and a delegation of the United Nations, will hold talks tomorrow in Istanbul on the safe shipment to international markets of grain waiting in Ukrainian ports," Akar said.
A Russian foreign ministry spokesman confirmed the meeting but also insisted that Moscow had a list of demands.
"Another round of expert consultations is planned for July 13 in Istanbul," ministry spokesman Pyotr Ilyichev was quoted as saying by Russia's Interfax news agency.
"Our understandable conditions include the possibility to control and search the ship to avoid the contraband of weapons, and Kyiv's commitment not to stage provocations," Ilyichev said.
Turkey has been sending defense delegations to both Moscow and Kyiv in a bid to break the deadlock over Ukraine's grain.
A plan proposed by the United Nations would see the shipments start along specific corridors that avoid known locations of mines.
Ukraine has refused to de-mine the area out of fear that Russia might then stage an amphibious assault on cities such as the Black Sea port of Odessa.
This report was produced with data from Reuters and Agence France-Presse