Kyiv, Feb. 25 -- The issue of countries across the world buying Russian oil found an echo as European leaders and lawmakers gathered in the Ukrainian capital on Tuesday to mark the fourth anniversary of Russia's invasion, with former UK premier Boris Johnson backing US President Donald Trump's move to get India to stop buying Russian hydrocarbons. Much of the discussion at the special meeting of the Yalta European Strategy focused on what Europe can do to increase pressure on Russian President Vladimir Putin for a negotiated end to the war in Ukraine, with proposals ranging from steps by individual European countries such as Britain and France to hand over frozen Russian assets to Ukraine, in order to get around divisions within the Europea...