watch now
Former President Barack Obama warned Donald Trump against hiring Mike Flynn as his national security adviser, three former Obama administration officials tell NBC News.
The warning, which has not been previously reported, came less than 48 hours after the November election when the two sat down for a 90-minute conversation in the Oval Office.
The revelation comes on a day that former acting Attorney General Sally Yates is expected to testify that Flynn misled the White House about his contacts with Russia's ambassador to the United States.