"I can't wait to salute our athletes, and I can't wait to share in the joy of your triumphs," he said.
Human rights groups had urged Bush to boycott the opening ceremonies to oppose China's crackdown on protesters in Tibet. The Bush administration argues that the Olympics are a sporting event not to be politicized, and that the president will raise human and religious rights with Chinese officials in the appropriate context.
But while talking to the athletes about their responsibilities in Beijing, Bush had a subtle message for China itself.
"You will convey our nation's most cherished values," the president said. "As ambassadors of liberty, you will represent America's love for freedom and our regard for human rights and human dignity ... to other athletes and to the people of China."
Bush beamed with pride at Team USA.
"We send you off with congratulations on the success you have already achieved, and on the accomplishments we know will be yours in Beijing," he said. "We're looking forward to rooting for you in Beijing."
The president and his wife, Laura, also were holding a White House dinner in the evening to honor current and previous U.S. Olympians.
Among those attending alongside officials from the Bush administration and the U.S. Olympic Committee are athletes such as track and field gold medalist Jackie Joyner-Kersee and gymnastics gold medalist Shannon Miller.
The menu was not a low-cal affair, with pea soup with duck pastrami, cheese puffs, crispy black sea bass, butter beans, salad and a dessert called the "Olympic Torch," a dark chocolate tart with raspberries and a blown-sugar Olympic flame.
The bluegrass band Seldom Scene was the chosen entertainment.
