Armstrong won a record sixth Tour de France in July

Armstrong has not competed since his last Tour win and opted to miss out on the Olympics in Athens, leading to speculation over his long-term future.

And he told l'Equipe newspaper: "Honestly, I don't know whether I'll be at the start of the Tour.

"This year, I achieved a dream. I won a sixth Tour and I made history. Now it's time to try something else."

Armstrong's team boss Johan Bruyneel earlier said the Texan's chances of going for win number seven were a "50-50 possibility".

But Armstrong said: "There are a lot of other things I'd like to accomplish on a bike before I retire. And I tell myself 2005 could be the right time to give it a try.

"I prefer for it to be flexible for I want to be free to decide at any given time about my participation in any given race.

"If it's the Tour, then I'll make a decision when it suits me. It'll be the same for Paris-Roubaix."