Dmitry Medvedev, deputy chairman of Russia's Security Council, attends a military parade on Victory Day, which marks the 77th anniversary of the victory over Nazi Germany in World War Two, in Red Square in central Moscow, Russia May 9, 2022. 

One of President Vladimir Putin's closest allies warned the West on Thursday that the increasing military support given to Ukraine by the United States and its allies risked triggering a conflict between Russia and the NATO military alliance.