WASHINGTON (Reuters) – U.S. President Joe Biden is meeting his national security team on Monday about Russia and Ukraine, a White House official said, as Russian President Vladimir Putin weighed a request by two regions of eastern Ukraine to be recognized as independent, a move that could give Moscow a reason to openly send in troops. Speaking on condition of anonymity, the White House official made the comments after a Reuters eyewitness saw Secretary of State Antony Blinken, Defense Secretary Lloyd Austin and General Mark Milley, chairman of the U.S. Joint Chiefs of Staff, arrive at the Whit…