US politicians have raised concerns about the threat of attacks at the upcoming Winter Olympics in Sochi, with one faulting Russia for not sharing intelligence.

"The threats are real. They are basically calling for attacks on the Olympics. I think you're going to see attempts to do that," said Michael McCaul, the chairman of the House Homeland Security Committee, in an interview from Moscow with ABC's This Week.

Mr McCaul said Russian authorities were taking the threats seriously, deploying 100,000 security officials to erect a "ring of steel" to secure the Sochi airport, mountain trains and the Games themselves.

If there were attacks, he said, they would more likely be directed at soft targets such as transportation.

The Republican congressman added that the diplomatic security corps said it was getting good cooperation from the Russians.

It noted that two dozen FBI agents were assigned to the games.

"It could be a lot better. I want to press that while here," he added, saying he wanted to know more about emergency evacuation planning.

Another key congressman, House Intelligence Committee chairman Mike Rogers, said Russian authorities were clearly concerned about security.

"But we don't seem to be getting all of the information we need to protect our athletes in the games," he said on CNN's State of the Union.

Mr Rogers, a Republican, said the Russians' unwillingness to share information with US intelligence was "a departure of cooperation that is very concerning to me".

"So what we're finding is they aren't giving us the full story about what are the threat streams, who do we need to worry about," the politician said.

"Are the terrorist groups who have had some success, are they still plotting?" Mr Rogers continued.

"There's a missing gap and you never want that when you're going into something, I think, as important as the Olympic Games," he said.

The Games open 7 February in Sochi, a resort city on the Black Sea coast.

The Irish Olympic Council has said that they are hoping to have between three and five people competing for Ireland at Sochi.

Elsewhere, Jamaica's bobsleigh team are on the verge of making the Sochi Olympics.

They have admitted they may need €59,000 to fund a dream that once inspired a Hollywood movie.

The sun-kissed Caribbean country, where average temperatures hit a sultry 28C degrees, hope to have their two-man bob confirmed in the Winter Olympics line-up tomorrow by the International Bobsleigh and Skeleton Federation.