Williams, who helped the Americans win the gold medal in Beijing in 2008 and defend their title last month in London, said he loves representing the U.S. and wouldn't rule out returning for a third Olympics in four years.
"I'll be 32, so I'm not going to be too old," Williams said. "[Jason] Kidd was 36 the last time we did it, so I could play two more essentially. But we'll see, we'll see what happens. Four years is a long ways off."
Formally called the world basketball championship, the World Cup of Basketball will be held in Spain in two years and the Americans are qualified with their Olympic title. Williams originally planned to play for the U.S. before pulling out of the 2010 worlds, a lesser event in the U.S. that NBA and world basketball officials are trying to strengthen.
"They're starting to try to put emphasis on it and make it more important," Williams said. "It's definitely important. I think the world championship is great. It's not the Olympics, but it is a big deal."
For now, the All-Star guard is focused on the Nets' debut in Brooklyn. He posted a picture on Twitter of players working out Monday and expects the team to be strong in its first season since leaving New Jersey.
Williams decided to stay with the Nets in July, signing a five-year contract worth about $98 million instead of joining his hometown Dallas Mavericks. The team also acquired All-Star Joe Johnson from Atlanta while re-signing Gerald Wallace, Brook Lopez and Kris Humphries.
"People sleep on us and we'll let them do that. That's fine," Williams said. "We have no excuses. I think everybody's at the point in their career where they want to win. There's no hidden agendas, there's no contract issues. Pretty much everybody's locked in and ready to focus on basketball."
Williams was set for Tuesday's debut of his first video game cover, "NBA Baller Beats" for Kinect for Xbox 360. The game teaches players dribbling and ball-handling skills by forcing them to dribble a real ball to the rhythm of 30 songs while keeping their head up to watch the screen in front of them.
While Williams was doing interviews about the game Monday in New York, the Mavericks were introducing five players they did land in the offseason: Elton Brand, O.J. Mayo, Chris Kaman, Darren Collison and Dahntay Jones, at a press conference in Dallas.
But the goal was Williams. The Mavericks trimmed payroll after winning the 2011 NBA title so they would be in position for a run at Williams, and the point guard said he didn't question the strategy of owner Mark Cuban and general manager Donnie Nelson.
It almost worked.
"Very tough decision," Williams said of re-signing with the Nets. "Days where I thought I was going to be a Maverick, days where I thought I was going to be a Net. Just couldn't really come to a decision. Actually, I just kept going back and forth."