Russia–Ukraine relations Ukraine's Infrastructure Minister Volodymyr Omelyan says the ports of Berdiansk and Mariupol are effectively under blockade as Russia refuses to let any Ukrainian vessels leave or enter the Sea of Azov. President Petro Poroshenko calls on NATO to send warships to patrol the Sea of Azov. Ukraine president calls for Nato warships in Sea of Azov © The Guardian Sources: Reuters The Guardian
