Russia and Turkey voiced support for a safe corridor in the Black Sea that would allow for Ukrainian grain exports. The support came as Turkish Foreign Minister Mevlut Cavusoglu hosted his Russian counterpart Sergey Lavrov in Ankara on Wednesday.

Russia also demanded Ukraine remove mines from the Black Sea. Ukraine is one of the world’s largest exporters of wheat, corn and sunflower oil, but a blockade of its ports have halted much of that flow, endangering food supplies to many developing countries, especially in Africa. Many of those ports are now also heavily mined.

“Until recently, the Ukrainian government, including President Zelenskyy, have denied their readiness to demine those coastal waters to begin this process,” Lavrov said. “If the Ukrainian side – as our Turkish friends tell us – is ready to either demine or grant the passage through the minefields, then let’s hope this problem will be solved.”

The meeting between Lavrov and Cavusoglu was set to discuss a United Nations proposal to free Odesa and Ukraine’s other Black Sea ports and allow 22 million tons of grain sitting in silos to be shipped out. U.N. Secretary-General Antonio Guterres has been working on a package for weeks that would also enable Russia to export grain and fertilizer to global markets.

“Ukraine’s food production and the food and fertilizers produced by Russia must be brought back into world markets despite the war,” Guterres said Wednesday. “The war, together with the other crises, is threatening to unleash an unprecedented wave of hunger and destitution, leaving social and economic chaos in its wake.”

Ukraine rejected the proposal, calling it not credible. On Thursday, Ukrainian President Volodymyr Zelenskyy called for long-term sanctions against Russia for provoking a global food crisis by blocking grain exports from Ukrainian ports.

“Russia’s war against our country must end as soon as possible to guarantee the security of food supplies across the Black Sea,” Zelenskyy said. “Ukrainian agricultural exports play a stabilizing role in the global market and Russia must be held accountable for provoking a new wave of migration against Europe, using the people of both Africa and Asia simply as hostages.”

The Associated Press contributed to this report.