With exactly one week before the Olympic torch is set to arrive at the Tower of London, officials are working to shore up security for the 2012 Olympic Games.

The British government Thursday put an extra 1,200 troops on standby in addition to the 3,500 already in place after contractor G4S failed to supply enough guards for the games.

The firm has a $444 million government contract to provide 10,400 security staff but only about 4,000 guards are trained and ready.

The G4S recruits will perform tasks including venue perimeter security, such as manning x-ray machines, searching people, searching vehicles, and operating closed-circuit television systems, the company said.

Culture Secretary Jeremy Hunt said that even in light of the security shake up, there is no need to deploy extra troops. He added that the 1,200 troops are on standby so that they can be moved within 48 hours if needed.

"The integrity of the plans remain absolutely intact, and people from all over the world should be completely reassured that this will be a safe and secure Olympics," Hunt said.

There are around 100 Olympic-related venues needing security during the London Games.