Earlier this year Speaker of the House Nancy Pelosi visited Damascus for a widely-publicized meeting with Syrian leader Bashar Assad.

The administration imposed sanctions on Syria in May 2004. The sanctions, legislated by Congress in 2003, had been since renewed on an annual basis and were scheduled to expire on May 11, 2007.

"Because the actions and policies of the Government of Syria continue to pose an unusual and extraordinary threat to the national security, foreign policy, and economy of the United States," a White House statement on May 9 said, "the national emergency declared on May 11, 2004, and the measures adopted on that date and on April 25, 2006, in Executive Order 13399, to deal with that emergency, must continue in effect beyond May 11, 2007.

The White House said the extension of sanctions was meant "to deal with the unusual and extraordinary threat to the national security, foreign policy, and economy of the United States constituted by the actions of the government of Syria."

"I declared a national emergency authorizing the blocking of property of certain persons and prohibiting the exportation or reexportation of certain goods to Syria," Bush said.

Bush said Syria continues to work to occupy Lebanon, pursue weapons of mass destruction and missile programs, and support the Sunni insurgency in Iraq. The administration said Syria has been arming the Iranian-sponsored Hizbullah and Palestinian insurgency groups.

"Syria should cease its interference in Lebanon and respond to Lebanon's entreaties to demarcate the border between the two countries and establish normal diplomatic relations," a senior administration official said.

On Thursday, a Syrian dissident, arrested after meeting White House officials in 2005, was convicted and sentenced to 12 years in prison. Kamal Labwani was convicted on charges of contacting a foreign country and inciting attacks against Syria. The United States has called on the Assad regime to release Labwani.