MADRID (AP) — Turkish President Recep Tayyip Erdogan is expressing optimism that humanitarian corridors could be opened to enable the export of Ukrainian grain to the rest of the world amid Russia’s war.

Tens of millions of people across the world are at risk of hunger as the four-month war has disrupted shipments of grain from Ukraine.

Speaking during a meeting with U.S. President Joe Biden on the margins of the NATO summit, Erdogan said, “We are trying to solve the process with a balancing policy. Our hope is that this balance policy will lead to results and allow the possibility to get grain to countries that are facing shortages right now through a corridor as soon as possible.”

“There are countries deprived of the grains, and we will open corridors and we will allow them to have access to the grains that they so need,” he added.

Turkey has played a central role in negotiations with Russia and Ukraine to try to reach an agreement that would allow for an increase of the amount of grain that can get out of Ukraine amid the conflict.

Some grain was transported west by rail out of Ukraine, but experts say restoring Ukraine’s ability to export grain through the Black Sea is necessary to have a significant effect on easing global food shortages.

Erdogan said that, “Steps to strengthening NATO would also contribute to the Russia-Ukraine process.”

During their meeting, Biden praised Erdogan for dropping his opposition to Finland and Sweden joining NATO and for “all the incredible work you’re doing to try to get the grain out of Ukraine.”

He said the pair would discuss both issues during their meeting.

Biden added: “You’re doing a great job, I just want to thank you.”