Addressing the UN general assembly in New York, Mr Bush urged its members to join the US in employing "diplomatic leverage to help the Burmese people regain their freedom".
He said the US would tighten economic sanctions on leaders of Burma's military junta and its financial backers, imposing visa bans on those responsible for human rights breaches and their families.
Mr Bush said Americans were "outraged" by the military junta's "19-year reign of fear".
He accused the regime of a range of abuses including the persecution of ethnic minorities, forced child labour, human trafficking and the detention of "more than 1,000 political prisoners".
The US president said the members of the general assembly should be guided by the universal declaration of human rights.
"The first mission requires liberating people from tyranny and violence," he added.
He also had strong words for the regimes in Sudan, where he said innocent civilians were suffering, and Zimbabwe - accusing president Robert Mugabe of an "assault" on the country's citizens.
Mr Bush said the "long rule of a cruel dictator" was coming to an end in Cuba - a reference to the recent health problems suffered by Fidel Castro, a longstanding thorn in Washington's side.
He claimed people in Lebanon, Afghanistan and Iraq had "asked for our help", and condemned the "hateful vision" of extremists.
However, the US president was surprisingly reticent on Iran prior to a scheduled speech by the Iranian president, Mahmoud Ahmadinejad - who was in the audience - to the general assembly later today.
He said he was "disappointed" by the focus of the UN human rights commission on Israel instead of governments including Iran and North Korea.
Yesterday, Mr Ahmadenijad played down the prospect of war between the US and Iran, describing talk of conflict as "a propaganda tool".
