Australia flag bearer Alex Pullin has revealed that the sight of Russian defences on his flight into the 2014 Sochi Winter Olympics has eliminated fears over a potential terrorist attack.

Several extremist groups have threatened to hijack the Games, which officially begin on Friday, with the opening ceremony scheduled for 3pm GMT.

However, snowboarder Pullin is confident that the hosts' stringent security measures will ensure everybody's safety.

"No, not at all," Pullin told reporters when asked if he was nervous about potential threat. "I'm sure it's secure and everything is completely under control.

"We flew in over navy ships that were floating out in the water, all surrounding the airport, and later when we looked out the window there was a military officer manning once every 20m. There's such a security lock down on the whole thing, and this event is taken very seriously."

Pullin was chosen ahead of skier Lydia Lasilla to carry the Australian flag in Sochi.