This follows bomb attacks on consecutive days last month that collectively killed 34 people and have heightened fears over more attacks by insurgents from the unstable Chechnya region - which lies just 200 miles from Sochi - over coming weeks.

Comey, who took over the helm of the FBI last year following the resignation of Robert Mueller said that although security at the Games is ultimately Moscow's responsibility, the agency is willing to help Russia.

About two dozen agents and other personnel will be sent to Moscow and more than a dozen others will be based in the Black Sea resort itself with some of them having already been deployed, he revealed. 

This follows a pledge made on the sidelines of the G8 leaders summit last June that US and Russian security forces would work together to maintain security ahead of the Games.

In a joint statement respective leaders Barrack Obama and Vladimir Putin said that "providing security for major sporting and public events, including the Winter Olympic Games in Sochi, is to be an important area of interaction".

Russian and US leaders Vladimir Putin and Barrack Obama vowed to work together to maintain security in a joint message last year ©Getty Images



When announcing the deployments Comey reiterated the concerns by admitting that "securing any Olympics is an enormous task", and that it would be "particularly challenging in Sochi because of its proximity to areas of unrest and sources of a terrorist threat".

Several US anti-terrorism experts have today expressed concerns about Russia's ability to maintain security, with House Homeland Security Chairman Michael McCaul warning ABC News of the danger of "soft" targets such as hotels, restaurants, malls and transportation which are outside the perimeter of heavily fortified areas.

But Comey expressed confidence Russia will keep the Games safe, insisting he thinks the Russian Government "understands the threat and is devoting the resources to address it".

This follows this week's launch of the biggest security operation in Olympic history with more than 30,000 police and Interior Ministry troops being deployed.

A new anti-terror operation was also introduced yesterday following the discovery of six bodies in four cars in the in the Stavropol region, 186 miles east of Sochi.

The area lies close to Chechnya, where insurgents, including warlord Doku Umarov, are seeking an Islamic state independent of Russia and are using what has been described as the "Satanic Games" in Sochi as a platform to broaden their appeal.