Legislation signed Tuesday by President Bush will tighten sanctions against Myanmar's ruling military regime by blocking the importation of precious gemstones to the United States from the southern Asian country.

The legislation will eliminate a significant source of funding for the country's corrupt military junta, which earns more than $300 million annually from the sale of gems, mostly rubies and jade, according to a release from the office of U.S. Rep. Joe Pitts.

Pitts, a Chester County Republican who represents Lancaster, was a co-sponsor of the bill.

A longtime advocate for the people of Myanmar, Pitts has visited the area's refugees and has worked for the rights of the ethnic minorities who the ruling military government has sought to eradicate because they believe the minorities are ethnically inferior, the release states.

"I have seen firsthand the people who are being victimized by this group, and I conveyed what I saw to Congress, the Pentagon, ambassadors …," Pitts said Tuesday. "I've been working on this for many years. It was time to send a message that this is not acceptable."

First lady Laura Bush was the administration's highest-profile spokesperson on the issue and was present Tuesday when the president signed the bill. Bush also signed a bill extending sanctions established in 2003, which must be renewed annually.

Myanmar, also known as Burma, has been under military rule since 1962. The current government took power in 1988 after crushing prodemocracy demonstrations at a cost of an estimated 3,000 lives.

The goal of the legislation signed Tuesday is to put enough financial pressure on Myanmar's military to encourage a change to a democratic civilian government.

More than 90 percent of the world's rubies and fine jade come from Myanmar, but records show only 3 percent of U.S. imports originate there, according to Pitts.

To evade existing sanctions, the regime disguises gem sales through dealers and financial institutions in neighboring countries.

Taking that into account, the legislation was designed to prevent the Myanmar military from profiting from sales to the United States and block the regime's bankers from accessing the U.S. financial system. It also bans Myanmar rulers from traveling to the United States and eliminates the requirement for annual renewal of existing sanctions under the 2003 Burmese Freedom and Democracy Act.

The 11,000-member Jewelers of America, a national association of jewelers, and such major jewelers as Tiffany & Co. and Bulgari support the ban, Pitts said.

"Obviously, this will slow down the flow of certain gems into the (United States)," Pitts said. "That said, I can't say how or if the price of gems might be affected."

The gem ban also is supported by the American Federation of Labor-Congress of Industrial Unions because of abusive labor conditions in Myanmar mines, Pitts said.

The Associated Press contributed to this report.

E-mail: jtodd@lnpnews.com