washington white house national security adviser michael flynn privately discuss u.s. sanction russia moscow ambassador unite state month president donald trump take office washington post report thursday cite unnamed current former u.s. officials post say senior u.s. officials interpret contact potentially illegal signal russia could expect reprieve sanction impose obama administration december reuters could immediately confirm washington post report reuters report last month cite three source familiar matter flynn hold five phone call russian ambassador sergei kislyak dec. 29 day then-president barack obama retaliate moscow allege interference 2016 u.s. presidential election post say flynn wednesday deny discuss sanction russian ambassador thursday back away denial spokesman flynn indicate recollection discuss sanction certain topic never come post quote spokesman say officials say week fbi continue examine flynn contact kislyak accord paper several officials emphasize sanction discuss see evidence flynn intent convey explicit promise take action inauguration post say trump adviser discuss sanction russian envoy washington post