WASHINGTON -- President George W. Bush on Tuesday renewed a ban on imports from military-ruled Myanmar and also signed a new law that aims to keep Myanmar's gems from entering US markets via third-party countries.

"On the Burmese regime, our message is: the United States believes in democracy and freedom," Bush said during a White House ceremony in which he signed the two laws.

The Burmese Freedom and Democracy Act, referring to Myanmar's former name, renews a sanctions regime imposed since 2003 over the suppression of opposition leader Aung San Suu Kyi's democracy movement.

Bush also signed a new sanctions regime aimed at stopping gems including jade and rubies from entering the United States via third nations such as Thailand, China, Taiwan, Malaysia and Singapore.

The so-called Tom Lantos Block Burmese JADE Act will deprive its ruling junta of hundreds of millions of dollars in annual revenue.

The gems trade is one of the most lucrative sources of profit for the military rulers, accused of blatant human rights abuses and stifling democratic opposition.

The bill also makes the generals and their families ineligible for visas to the United States and enhances existing financial sanctions against the regime.

It includes new reporting requirements that will provide greater transparency about the junta in terms of financial holdings, information about countries that provide military aid to the regime, and background on Myanmar's timber trade, Senate Republican leader Mitch McConnell has said.

The White House reiterated its position that sanctions have been effective at shutting off sources of revenue for the junta's coffers.

"We do know that sanctions can work, which is why we work both unilaterally and multilaterally to impose them, to help squeeze the regime," White House spokeswoman Dana Perino told reporters Tuesday.

"Our goal is to squeeze the people who are actually repressing the people, and not hurt the people."

An earlier version of the legislation was introduced last year by human rights advocate Tom Lantos, a senior lawmaker who died of cancer in February, in response to the junta's deadly crackdown of peaceful protests.

But Congress began to consider it in the aftermath of a cyclone that ravaged the country earlier this year, when the junta blocked entry to many foreign aid workers and relief shipments, relenting only after a personal visit by UN Secretary General Ban Ki-moon.

The disaster left at least 138,000 missing or dead.

The new legislation also urged US energy giant Chevron to consider divesting from a lucrative gas project if the junta did not embrace reforms.

Lawmakers had dropped a plan to impose sanctions that would have pressured Chevron to pull out from the Yadana gas project after the company argued that other firms from nations such as China and India could easily take over its stake if divested.