The United Nations, Turkey and Ukraine pressed ahead to implement a Black Sea grain deal and agreed on a transit plan for Monday for 16 vessels to move forward, despite Russia's withdrawal from the pact that has allowed the export of Ukrainian agricultural products to world markets.

Russia, which invaded Ukraine on. Feb 24, on Saturday halted its role in the Black Sea deal for an "indefinite term," cutting shipments from one of the world's top grain exporters, because it said it could not "guarantee safety of civilian ships" traveling under the pact after an attack on its Black Sea fleet.

The move has sparked an outcry from Ukraine, NATO, the European Union and the United States, while the United Nations and Turkey, two main brokers of the July deal, scrambled on Sunday to save it.