Russia and Ukraine signed separate agreements Friday to reopen blockaded Ukrainian ports and allow grain exports to begin to flow.

Why it matters: Ukraine is one of the world's top exporters of wheat, sunflower oil and other agricultural products. With those exports almost entirely blocked due to Russia's Black Sea blockade, the food crisis plaguing countries in Africa and elsewhere has deepened.

The big picture: The deal, which was brokered by the UN with the help of Turkey, would be in place for 120 days and can be renewed, UN officials said.

• Under the agreement, Ukrainian captains will help guide the ships carrying the grain out of Odesa, Ukraine's largest port, and two neighboring ports through safe channels mapped by Ukraine's Navy. Ukraine has mined its ports to defend against a Russian naval incursion.
• The passage of the vessels will be monitored by a control center in Istanbul.
• Ukrainian presidential adviser Mykhailo Podolyak said earlier Friday that Ukraine and Russia would sign separate agreements, stressing that Kyiv “does not sign any documents with Russia.”

What they're saying: “Today, there is a beacon on the Black Sea,” UN Secretary-General António Guterres said during the signing ceremony in Istanbul, which was also attended by Turkish President Recep Tayyip Erdoğan and ministers from Russia and Ukraine. “A beacon of hope, a beacon of possibility, a beacon of relief in a world that needs it more than ever.”

• “Since the war started, I have been highlighting that there is no solution to the global food crisis without ensuring full global access to Ukraine’s food products and Russian food and fertilizer,” he added.
• “It will bring relief for developing countries on the edge of bankruptcy and the most vulnerable people on the edge of famine."

Context: Key factors of the UN and Turkish-led talks included who would escort ships into and out of the ports, how their safe passage could be guaranteed, and how Ukraine could be certain Russia would not use any agreement to its military advantage.

• Podolyak warned Friday that any Russian "provocations" would be met with "an immediate military response."
• The negotiations also involved ensuring Russia can export grain and fertilizer despite Western sanctions.

Editor's note: This story has been updated with additional details after the signing ceremony.