The US Senate gave final approval late Wednesday to legislation imposing sanctions on Myanmar's ruling military junta, and was to send the bill to US President George W. Bush, who said he was eager to sign it.
The Burmese Freedom and Democracy Act of 2003, passed in the Senate Wednesday by a vote of 94-1, authorizes Bush to aid Myanmar's democracy activists, impose trade restrictions, freeze the regime's financial assets in US banks and impose a visa ban on regime members seeking to enter the US.
A White House statement said Bush looked forward to signing the bill.
"This legislation sends a clear message to the Burmese regime that their continued detention of Nobel Peace Laureate Aung San Suu Kyi and their assaults on freedom cannot stand," said Scott McClellan.
The legislation seeks to punish the ruling junta for its recent crack-down on pro-democracy groups and its detention on May 30 of opposition leader Aung San Suu Kyi.
The author of the bill, Senator Mitch McConnell, applauded the US Congress for the legislation's speedy passage and said he hoped it would trigger the start of the dictatorship's demise.
"Democracy and the rule of law will prevail in Burma," he said.
"We must never tire in the pursuit of justice in long-suffering Burma until Suu Kyi is free and the struggle for freedom won."
Aung San Suu Kyi's National League for Democracy NLD won 1990 elections in a landslide but has never been allowed to take power.
Myanmar is facing increased pressure to release the Nobel peace laureate who was taken into "protective custody" after clashes broke out during a political tour of northern Myanmar in May, when hundreds of pro-junta militants attacked her supporters. Dissidents say dozens were killed in the violence.
Shortly after the Senate vote, UN Secretary General Kofi Annan emerged from a meeting with Myanmar deputy foreign minister U Khin Maung Win to urge the speedy release of Aung San Suu Kyi.
The Senate vote came one day after the US House of Representatives voted 418 to 2 to approve the measures.
The regime in Yangon condemned that vote, calling the move to tighten economic sanctions "weapons of mass destruction" that would create havoc.