President Bush has imposed economic sanctions on Syria. They include an export ban and flight restrictions.

The sanctions are in response to what the White House sees as a lack of action by Damascus on key issues.

For years, the United States has raised concerns about Syrian support for militant groups. More recently, the Bush administration has complained that Syria is not doing enough to stop anti-American insurgents from crossing its border into neighboring Iraq.

Last year, Congress voted to give the president the authority to impose sanctions. Mr. Bush signed the legislation in December 2003 with little if any fanfare and at first indicated he thought diplomacy should be given more time to work.

U.S. officials have indicated in recent days that patience was running thin. At the State Department, Spokesman Richard Boucher stressed that Syria was well aware of U.S. concerns. He said Secretary of State Colin Powell made America's position clear during talks last year in Damascus. ?We looked for Syria to understand the new situation and change some of the practices and policies that it had had, specifically in terms of support for terrorist groups, abandoning programs to develop weapons of mass destruction, contributing to stabilization in Iraq, withdrawing its troops from Lebanon,? he said.

Mr. Boucher said there was some movement, but not nearly enough. He said, overall, the change the administration hoped for never occurred.

?In some of those areas, we saw some action,? he said. ?I think we made clear all along that we didn't feel like there was a serious and comprehensive response. We've never felt that Syria adapted itself to the new realities.?

The president did not impose all the sanctions authorized by congress, but opted for a middle ground by banning exports and barring take-offs and landings in the United States by Syrian aircraft. Mr. Bush added on a few penalties not specifically mentioned in the legislation. They include restrictions on banking ties between U.S. financial institutions and the Commercial Bank of Syria. He also put a freeze on American assets held by certain Syrian citizens or entities deemed to have ties to militant groups, Syria's presence in Lebanon, the pursuit of weapons of mass destruction or the destabilization of Iraq.

The executive order implementing the sanctions also includes a warning to the Syrian government. It says if Damascus does not change its ways, further steps will be taken. Syrian officials have dismissed the U.S. sanctions, saying they will face any foreign challenges and their ramifications.