Members of Congress, including one from Michigan, say they have serious concerns about Americans' safety at next month's Olympics in Russia, and they want Moscow to cooperate more on security.
Russian President Vladimir Putin has promised his country will do all it can to ensure a safe Olympics.
The State Department has advised Americans planning to go that they should keep vigilant about security because of potential terrorist threats, crime and uncertain medical care.
Rep. Mike Rogers of Michigan says the U.S. doesn't seem to be getting all the information needed to protect American athletes, and that must change.
Rogers was on CNN's "State of the Union" and CBS' "Face the Nation."
Meanwhile, an Islamic militant group in Russia's North Caucasus has claimed responsibility for twin suicide bombings in the southern city of Volgograd last month and posted a video threatening to strike the 2014 Winter Olympics in Sochi.
There had been no previous claim of responsibility for the bombings, which killed 34 people and heightened security fears before next month's Olympics.
In the video, two Russian-speaking men sitting in front of black banners with Arabic verses warn President Vladimir Putin that if the games are held, "we will give you a present for the innocent Muslim blood being spilled all around the world."
They add that "for the tourists who come there will be a present, too."
The video was posted Sunday on the website of the militant group Vilayat Dagestan.
