FILE - In this Dec. 12, 2016 file photo, National Security Adviser-designate Michael T. Flynn waits for an elevator in the lobby at Trump Tower in New York. The Obama administration is aware of frequent contacts between President-elect Donald Trump’s top national security adviser Michael Flynn and Russia’s ambassador to the United States, including on the day President Barack Obama hit Moscow with sanctions in retaliation for election-related hacking, a senior U.S.