Bush's speech, outlining America's achievements and challenges in Asia as he wraps up eight years in office, came just hours before his flight to Beijing to attend the Olympics. China has rounded up opponents and slapped restrictions on journalists, betraying promises made when it landed the hosting rights.

Chinese officials earlier bristled at Bush's criticism and his meeting with Chinese activists at the White House last week. But Bush also has come under pressure to use his visit to press Beijing even harder for greater religious tolerance and other freedoms.

The White House's handling of the speech demonstrated the president's delicate balancing act. In what appeared to be an effort to ease embarrassment for China as it prepared for its splashy appearance on the world stage, the text of Bush's address was released to media about 18 hours before he delivered it in Thailand.

Then the president and first lady Laura Bush had a string of events Thursday clearly aimed at shifting the focus to the repressive military regime in neighboring Myanmar, which marks the 20th anniversary of a brutal crackdown on pro-democracy activists Friday.

Mrs. Bush, an outspoken advocate for Myanmar, also known as Burma, visited a border refugee camp in Mae La, home to 38,000 Karen, an ethnic minority that human rights organizations say is the target of an ongoing Myanmar military campaign marked by murders of civilians, rapes and razing of villages. She also went to a health clinic run by a woman known as the "Mother Teresa of Burma."

Meanwhile, the president was briefed at the U.S. ambassador's residence on the recovery from the cyclone that devastated Myanmar's heartland and killed more than 80,000 people in May, had lunch with nine Burmese activists and did an interview with local radio journalists in hopes of influencing events across the border.

Bush told the activists that the American people care for them deeply. The president said he wanted to hear their stories and get advice on how the U.S. can help their cause.

"I'm always inspired by acts of courage, and I'm having lunch with courageous people," he said.

Bush's speech had been expected to feature Myanmar, but contained only a brief - though blunt - mention of the reclusive nation that initially resisted outside aid after the cyclone. Its leaders reluctantly agreed while imposing tight restrictions on international aid agencies.

One of the world's poorest countries, Myanmar has been under military rule since 1962, and the latest junta came to power after brutally crushing a pro-democracy uprising in 1988. Mass street demonstrations, led by Buddhist monks, were again put down last September.

"Together, we seek an end to tyranny in Burma," Bush said, calling for the release of pro-democracy leader Aung San Suu Kyi and all other political prisoners. "We will continue working until the people of Burma have the freedom they deserve."

In perhaps his last major address in Asia, Bush said America speaks out for a free press, free assembly and labor rights not to antagonize China's leaders, but because it's the only path the potent U.S. rival can take to reach its full potential.

"America stands in firm opposition to China's detention of political dissidents and human rights advocates and religious activists," Bush said. "We press for openness and justice not to impose our beliefs, but to allow the Chinese people to express theirs."

As balance, Bush also offered praise for China's market reforms and hope that it will embrace freedom.

"Change in China will arrive on its own terms and in keeping with its own history and its own traditions. Yet change will arrive," he said.

Australian Prime Minister Kevin Rudd, speaking before flying to Beijing, also urged the international community "to speak with a strong and united voice" to maintain pressure on China over human rights, though he conceded Beijing's record has improved.

"Remember, it was not all that long ago they were in the middle of the Cultural Revolution with people getting put up against a wall and basically knocked off," he told Nine Network television.

Bush urged North Korea to live up to its promise to dismantle its nuclear weapons, adding, "The United States will continue to insist that the regime in Pyongyang end its harsh rule and respect the dignity and human rights of the North Korean people."

About 25 people around the convention center where Bush spoke welcomed him. But a Muslim group shouted "Bush, get out. God is great" as the presidential motorcade passed. The protesters handed out leaflets saying "George Bush is a war criminal."