Americans attending the Olympics are being urged to tone down the USA logo wear when in public areas.
The United States will be ready to rescue Americans from the upcoming Sochi Olympics, Defense Secretary Chuck Hagel said amid heightened security fears in the run-up to the Games.
"If we need to extract our citizens, we will have appropriate arrangements with the Russians to do this," Hagel told journalists on Friday.
Over 10,000 American athletes and spectators are expected to attend the Games, which start on Feb. 7.
Russia has the main responsibility for protecting the Olympics, but recent deadly suicide attacks have heightened worries about militant attacks.
On Thursday, the U.S. Olympic team and at least five other national delegations said they had received messages making terrorist threats ahead of the Games.
The threats arrived as Russian security forces were hunting for at least five suspected terrorists – some of them so-called “black widows” – who may be plotting attacks against the Olympic torch relay or the games themselves, according to notices posted in Sochi.
A four-minute video which had been posted by an ally of al Qaeda emerged Friday. In it, a militant likened the upcoming Olympics to those held under Adolf Hitler in 1936, and warned again of terror at the upcoming Sochi Games.
Russia has not asked for help or technology from the United States to help defend thousands of athletes and spectators expected, Hagel added.
"As of right now, the Russians have not requested any specific assistance or technology. We want them to know that if they need our help, we want to help," Hagel told Pentagon reporters on Friday.
The United States has already announced that it will station two warships nearby in the Black Sea during the Games.
The Associated Press contributed to this report.