Swiss tennis player Roger Federer speaks during a press conference at the Main Press Center (MPC) in London, Britain, July 26, 2012. [Chen Jianli/Xinhua]

World No. 1 Roger Federer said in London on Thursday that winning the Olympic Games could be even harder than winning a grand slam title.

Federer, who made history three weeks ago by winning his seventh Wimbledon title, said that win has helped to boost his confidence, but the Olympic has fewer rounds and could produce more upsets.

"I hope I can be the favorite...and be able to get going and get full fight on the court," Federer said at a press conference ahead of the London Olympic Games.

Federer and Swiss teammate Stanislas Wawrinka won the men's doubles gold medal at the 2008 Beijing Games but failed to clinch the men's single title, which was won by Spanish player Rafael Nadal.

Speaking on the withdrawal of Nadal from the London Games, Federer said he felt sad but expects the Spaniard to return to the court soon.

"It was a big surprise to see Rafa pull out of the Olympics as the defending champion from four years ago," Federer said. "I wish him a speedy recovery and hopefully we will see him on the tour again soon.

Federer does not rule out competing at the Rio Olympic Games in 2016.

"There is absolutely no plan to retire after this (London Games), and I have plans in place for next year and beyond that," the Swiss said. "Even if I do win, I will keep on playing."