– Russia and Ukraine sent defence and infrastructure ministers to Istanbul, Turkey
– They signed the landmark deal alongside U.N. gen sec and Turkish president
– The accord opens the way to significant volumes of vital commercial food exports from three key Ukrainian ports – Odesa, Chernomorsk and Yuzhny
– Russia had been blockading the ports, preventing essential grain from leaving
– The deal, seen by many as the first breakthrough in the conflict, comes after almost six months of war