Rockets strike Ukraine's Lviv as Biden says Putin 'cannot remain in power'

By Jarrett Renshaw and Natalia Zinets WARSAW/LVIV, Ukraine (Reuters) - U.S. President Joe Biden described Russian leader Vladimir Putin as a butcher who "cannot remain in power" after meeting Ukrainian refugees in Poland, as Kremlin forces stepped up attacks across Ukraine, including the western city of Lviv. Biden's comments, an escalation of U.S. rhetoric towards Moscow over its invasion of Ukraine, were not a call for regime change in Russia, a White House official said later, but meant to prepare the world's democracies for an extended conflict. Just before he spoke outside Warsaw's castle...