He said he had chosen Thailand as the springboard to deliver the important speech because "Thailand is a long-time friend and Thailand is an important member of Asean".
"In other words, the Far East is more than just the countries that dominate the news," he added.
Asked why Thailand, at this juncture in history, is still important to the United States, Bush said: "Common values, close friends. Hopefully, Thailand views us as a reliable ally. We certainly view Thailand as a reliable ally. And 175 years of relations between two countries is a long time."
Asked to cite the single most important pillar of Thai-US relations, the US president responded immediately: "Democracy." He also praised Thailand for its humanitarian treatment of refugees.
Bush will also meet Burmese dissidents in Bangkok. Asked whether First Lady Laura Bush will be speaking on behalf of democracy fighters in Burma, Bush replied: "I have no doubt about that."
Bush will raise the issue of human rights and religious freedom when he meets President Hu Jintao of China during the Olympic Games.
He stressed, however, that sports should not be politicised. "I am going to China this time as the US president who happens to be a sports fan," he said.
On Tuesday, Bush had an unannounced meeting in the White House with five leading Chinese dissidents. He told them he would continue to press China's leadership for reforms on human rights and religious freedom.
Bush assured them he would "carry the message of freedom" as he travels to Beijing.
The activists were prison critic Harry Wu, democracy activist Wei Jinsheng, Uighur activist Rebiya Kadeer, Bob Fu of the China Aid Association and writer Sasha Gong.
White House spokeswoman Dana Perino said in a statement that Bush had told the activists that engagement with Chinese leaders "gives me an opportunity to make the United States' position clear - human rights and religious freedom should not be denied to anyone".
Bush also dropped in on a meeting between China's Foreign Minister Yang Jiechi and US National Security Adviser Stephen J Hadley. He told the Chinese minister that hosting the Olympics "presents the Chinese with an opportunity to demonstrate compassion on human rights and freedom".
Bush has come under pressure from lawmakers and advocacy groups to make a public statement expressing Washington's concern about the crackdown on human rights and freedom in China.
The president has insisted that the Olympics are not a good opportunity to make political points. But Bush's aides have told reporters here that Bush prefers "quiet diplomacy" to making public statements that may embarrass the Chinese leadership.
A group of US congressmen are planning a resolution calling on Bush to make a statement of some kind on human rights in China before and after his trip to Beijing, to meet with families of jailed prisoners of conscience and even to seek to visit Tibet.
In a news conference while attending the G-8 summit in Japan last month, Bush said:
Bush's legacy Towards the end of the interview, a smiling, relaxed George Bush seemed ready for some personal questions.
What's going to be your legacy once you step down from office next January?
"I don't know. I will be dead by the time they figure it out."
How do you want history to remember you?
"Somebody who took on tough challenges and didn't shy away from doing what he thought was right.
"And, you know, look, I'm a big believer in freedom and liberty. That's been a hallmark of my agenda.
"But there's no such thing as short-term history, so I am very confident in telling you that I'll be long gone before somebody finally figures out the true merit and meaning of the Bush administration."