The two sides said that Russia and Ukraine, among the world’s biggest exporters of food, sent their defense and infrastructure ministers respectively to Istanbul to participate in a 1330 GMT signing ceremony.
U.N. Secretary-General Antonio Guterres, expected to co-sign the accord, and Turkish President Tayyip Erdogan were to attend.
But fighting continued unabated in Ukraine’s east, underlining deep-seated hostility and mistrust. A Kyiv presidential adviser said it would sign no documents with Russia, rather only parallel deals on grain exports with the United Nations.
The blockade by Russia’s Black Sea fleet has worsened global supply chain disruptions. Western sanctions imposed on Moscow stoked high food and energy prices inflation since Russian forces swept Ukraine on Feb. 24.
Officials did not immediately release full details of the accord. But, citing an unnamed source, Russian state news agency TASS said that three Ukrainian ports, including the biggest export hub, Odesa, would open again.
Diplomats said last week that the plan included Ukrainian vessels guiding grain ships through mined port waters, with Turkey overseeing inspections of ships to ease Russian concerns that they might smuggle weapons to Ukraine.
Some 20 million tonnes of grain are stuck in silos at Odesa, and dozens of ships have been stranded by Moscow’s attack.
Turkish Foreign Minister Mevlut Cavusoglu tweeted on Thursday that Friday’s gathering in Istanbul would mark “the first step to solve the current food crisis.”
The United States welcomed the deal and said it focused on holding Russia accountable for implementing it.