White House adviser says U.S. to keep sharing intelligence on Russia's Ukraine actions

White House National Security Adviser Jake Sullivan said on Sunday that a Russian invasion could begin any day and the United States will continue to share intelligence with the world to deny Moscow the ability to stage a surprise "false flag" operation to launch an attack.

Sullivan, speaking on CNN's "State of the Union" program, declined to say whether U.S. intelligence agencies believe that Russia is considering an attack on Wednesday, as some reports suggest.

"We cannot perfectly predict the day, but we have now been saying for some time that we are in the window, and an invasion could begin -- a major military action could begin -- by Russia in Ukraine any day now. That includes this coming week before the end of the Olympics," Sullivan said.