Bush signed the bill into law with no fanfare before leaving the White House for the Camp David retreat in Maryland. The White House announced the move Friday evening.

Bush is generally not enthusiastic about such restraints on his diplomatic options and, in a statement, signaled that was the case with this bill as well.

"My approval of the act does not constitute my adoption of the various statements of policy in the act as U.S. foreign policy," he said.

Syria long has been on the State Department's list of state sponsors of terrorism, along with North Korea, Sudan, Cuba, Iran and Libya. But Syria is the only country on that list to have full diplomatic relations with the United States.

The legislation says Syria has provided a safe haven for anti-Israel terrorist groups such as Hamas and Islamic Jihad and is accused of pursuing the development and production of biological and chemical weapons.

It states that Syria must end its support of terrorists, terminate its 27-year military presence in Lebanon, stop efforts to obtain or produce weapons of mass destruction and long-range ballistic missiles and interdict terrorists and weapons from entering Iraq.

If Syria fails to meet those conditions, the president must ban sales of dual-use items, which can have both civilian and military applications.

He also must impose at least two out of a list of six possible penalties: a ban on exports to Syria, prohibition of U.S. businesses' operating in Syria, restrictions on Syrian diplomats in the United States, limits on Syrian airline flights in the United States, reduction of diplomatic contacts or a freeze on Syrian assets in the United States.

At the White House's insistence, the law gives Bush broad leeway to waive both the dual-use ban and the two sanctions on the basis of national security, or after determining that Syria has taken the actions required.

In the past, the Bush White House and its predecessors have made liberal use of waivers to avoid disrupting diplomatic links.

In Syria's case, sanctions would probably have greater political than economic effect, as bilateral trade amounts to only about $300 million a year.

Though frustration remained, administration officials have cited signs of progress by Syria. They have said that Syria has taken steps to prevent anti-American terrorists and weapons from crossing its border with Iraq, offered more cooperation in searching for Iraqi frozen assets and lent support for a U.S.-sponsored U.N. Security Council on Iraq.

However, lawmakers who supported the bill said Damascus had fallen short in numerous other areas.

Following the bill's passage last month, Syria's Prime Minister Naji al-Otari dismissed the sanctions threat. He said in remarks published in the Egyptian magazine Al-Mussawar that they would have only a "very modest" effect. He also labeled the anti-U.S. fight inside Iraq a "liberation movement."