Russian, Ukrainian and Turkish military delegations met U.N. officials on Wednesday in a bid to break a monthslong impasse over stalled grain deliveries to world markets through the Black Sea, which has seen food prices soar and millions face hunger.

The summit in Istanbul, which started at around 4 p.m. local time, marks the Russian and Ukrainian governments’ first face-to-face talks since another meeting in the Turkish metropolis in late March.

Turkey has been working with the United Nations to broker a deal after Russia’s Feb. 24 invasion of Ukraine fuelled prices for grains, cooking oils, fuel and fertilizer.

Ankara has offered to provide safe Black Sea corridors and has held talks with the U.N., Russia and Ukraine to reach an agreement. The U.N. would establish a center in Istanbul to control the shipments, Turkish officials have said.

"We are working hard indeed but there is still a way to go," U.N. Secretary-General Antonio Guterres told reporters on Tuesday. "Many people are talking about it. We prefer to try and do it."

Diplomats said details of the plan under discussion were to include Ukrainian vessels guiding grain ships in and out through mined port waters; Russia agreeing to a truce while shipments move; and Turkey – supported by the United Nations – inspecting ships to allay Russian fears of weapons smuggling.

The summit in Istanbul is the run-up to talks between the Turkish and Russian military delegations, which took place in Moscow last month to discuss the sea route and the safe departure of vessels at Ukrainian ports.

‘Deal in reach’

Russia and Ukraine seem to have made progress but are sticking to firm demands that could collapse the talks.

Kyiv’s top diplomat earlier on Wednesday credited Guterres and the Turkish government for facilitating talks on grain shipments.

Ukrainian Foreign Minister Dmytro Kuleba said a deal to resume grain exports appeared very close, but he made clear that broader peace talks were frozen.

"We are ready to export grain to the international market... We are two steps away from a deal with Russia," Kuleba told Spanish newspaper El Pais before the talks in Istanbul.

"The security concerns, linked to Russia’s position, need to be addressed. We are in the final phase and now everything depends on Russia," he said.

Kuleba separately told the Associated Press (AP) that exports would not resume without security guarantees for ship owners, cargo owners and Ukraine as an independent nation.

He stressed any agreement needs to ensure Russia "will respect these corridors, they will not sneak into the harbor and attack ports or that they will not attack ports from the air with their missiles."

Asked why Moscow might be ready now to agree to a deal, Kuleba said he thought Russia wanted "to show the countries of Africa and Asia that they want to save them from food shortages." But he said Russia could still drag out talks.

Much is at stake

Ukraine is one of the world’s largest exporters of wheat, corn and sunflower oil, but Russia’s invasion and war disrupted production and halted shipments, endangering food supplies in many developing countries, especially in Africa, and contributing to higher prices.

Guterres and Turkey have worked for months to secure a deal that would allow Ukraine to export wheat and other commodities from Odessa, the country’s largest port, and also enable Russia to export grain and fertilizer to global markets.

The war has trapped about 22 million tons of grain inside Ukraine, according to Ukrainian President Volodymyr Zelenskyy.

U.N., Turkish and other officials are scrambling for a solution that would empty the silos in time for the upcoming harvest in Ukraine, which is at risk amid a shortage of storage space due to the halt in exports.

The U.N. Food and Agriculture Organization (FAO) says the war is endangering food supplies for many developing nations and could worsen hunger for up to 181 million people.

Some grain is being transported through Europe by rail, road and river, but the amount is small compared with sea routes.

Ukraine sparked hopes on Tuesday for an increase in grain exports despite Russia’s blockade, noting that ships had started to pass through an important mouth of the Danube river.

Russia is not able to transport its grain either. Moscow argues that Western sanctions on its banking and shipping industries make it impossible for Russia to export food and fertilizer and are scaring off foreign shipping companies from carrying it.

Ahead of the talks in Istanbul, a senior Russian diplomat said Moscow was willing to ensure safe navigation for ships to carry grain from Ukrainian ports but would press for its right to check the vessels for weapons – a demand earlier rejected by Kyiv.

Pyotr Ilyichev, the head of the Russian Foreign Ministry’s department for ties with international organizations, said Russia’s military had repeatedly declared its willingness to allow for safe shipping corridors in the Black Sea.

Seventy vessels from 16 countries have remained stuck in Ukrainian ports, Ilyichev said, alleging that Ukrainian authorities had barred them from departing.

"Our conditions are clear: We need to have a possibility to control and check the ships to prevent any attempts to smuggle weapons in, and Kyiv must refrain from any provocations," Russia's Interfax news agency quoted Ilyichev as saying.

News agency RIA quoted another diplomatic source as saying that Russia’s demands include the removal of "obstacles to the exports" created by Western sanctions.

"There are obstacles for the Russian side in the areas of ship insurance, logistics, transportation services and banking operations due to the sanctions imposed," RIA’s source said.

For its part, Ukraine stressed the U.N.’s importance to the negotiations but said it wanted its own set of security guarantees.

"We are grateful to U.N. Secretary-General Antonio Guterres for his active role in reaching for a solution that could guarantee the security of our southern regions," Ukrainian Foreign Ministry spokesperson Oleg Nikolenko told Interfax-Ukraine.

Diplomatic efforts

President Recep Tayyip Erdoğan has tried to use his good relations with Russian counterpart Vladimir Putin and Kyiv’s leader Zelenskyy to find a solution and continue negotiations about Ukraine.

Erdoğan is due to meet Putin for the first time since Russia’s invasion when the two leaders are hosted by Iranian President Ebrahim Raisi in Tehran next Tuesday. The talks are officially due to focus on the situation in war-ravaged Syria.

But the Kremlin said Putin and Erdoğan will also hold a separate meeting that is almost certain to focus heavily on Ukraine.

In a phone call on Monday, Erdoğan told Putin that it was time to act on a U.N. plan to set up a sea corridor for Ukrainian grain exports through the Black Sea.

Erdoğan on Monday also held talks with Zelenskyy, during which the leaders stressed the need to unblock Ukraine’s ports and resume its grain exports.

"We appreciate (Turkish) support. Discussed the importance of unblocking (Ukrainian) ports and resuming grain exports. We must also prevent Russia from taking our grain from (occupied territories)," Zelenskyy tweeted.

A plan proposed by the United Nations would see the shipments start along specific corridors that avoid known locations of mines.

Experts say demining the Black Sea is a complex operation that could take months – too long to address the growing global food crisis.