Lance Armstrong has set his sights on Olympic gold after retaining his Tour de France crown.

Armstrong, who defied the doubters 12 months ago when he returned after fighting off testicular cancer to become only the second US winner of the event after three-time winner Greg LeMond, headed off nearest challenger and 1997 winner Jan Ullrich of Germany by just over six minutes to take the overall title.

Now the target is to see off Ullrich's challenge again in Sydney and Armstrong said: "I think I can win if I'm in good form - and winning a gold medal would be very special."

Americans might not understand the difference between a time-trial and a sprint, a mountain stage or a flat ride. But the sound of the American anthem on an Olympic podium would be more familiar and a more significant achievement for Armstrong.

That is why Armstrong cannot afford to go wrong. He announced he would focus on the time-trial title in Sydney at the expense of the road race. "I'll probably start both races but I'm going to concentrate on training for the time-trial. It's not the same preparation at all" he said.

The American would probably stand an excellent chance in the road race but he said he would enter it above all to help compatriot George Hincapie. "It'll be a lottery," Armstrong said of the flat and easy design of the Olympic course.

Armstrong was once probably the best specialist of circuit races such as the Olympic road contest, as he showed in winning the world championship in 1993 in Oslo as a virtual unknown.

He had a first attempt at Olympic glory at home at the 1996 Atlanta Olympics, in which he tried in vain to break away from his rivals before bowing to Switzerland's Pascal Richard in the road race.

But it was in the days before his cancer, when Armstrong was a different rider. Having won four of the five individual time-trials held in the Tour these past two seasons, the Texan will be the top favourite in Sydney. "But I first want to recover from the fatigue of the Tour," he said.

He even says he will not be the man to beat in Australia. "For me the favourite has to be Ullrich. He's a very talented rider," Armstrong said.

Ullrich will certainly be out for revenge after being outclassed by Armstrong in the Tour and finishing second for the third time.

And if the Olympics mean a lot for an American, they certainly mean as much for a former East German.

Speaking of his win on Sunday, before heading off for a cancer research function, Armstrong said: "It was a hard Tour. It's very special - but I'm glad it's finished." He will now make several guest appearances in the United States before returning to his home in Nice to prepare for the Olympics.