President Bush announced Thursday the United States will freeze the property and interests of people deemed to be undermining Lebanon's democratic government.

Bush's executive order targets anyone found to be helping Syria assert control in Lebanon or otherwise trying to break down the rule of law, including by means of violence.

"Such actions constitute an unusual and extraordinary threat to the national security and foreign policy of the United States," Bush said in an accompanying message to Congress.

Bush's order also applies to spouses and dependent children of those deemed to be contributing to instability in Lebanon, and to those providing aid to such people.

The treasury secretary, in consultation with the secretary of state, will designate the people affected by the order. They will not be able to do business with U.S. residents, and their identity will be announced to the international financial community.

Bush in June barred U.S. entry to people deemed to be undermining Lebanon.

"All of these orders and presidential determinations related to Lebanon are saying, from the United States, that Syria needs to quit meddling in Lebanon's affairs," said Gordon Johndroe, Bush's national security spokesman.

The United States has limited diplomatic ties with Syria because of its support of Hezbollah and Hamas, which the United States considers terrorist organizations.

Bush says Lebanon's sovereignty is constantly under attack.

The June 13 car bomb assassination of lawmaker Walid Eido was a blow to the stability of the small Mediterranean nation, which has been mired in a political power struggle between the government and the Hezbollah-led opposition, supported by Syria.

Eido was a close friend of former Prime Minister Rafik Hariri, who was assassinated in a massive bombing in Beirut in February 2005 along with 22 others. Eido also was a political ally of Hariri's son, Saad, who now leads the anti-Syrian majority in the Lebanese parliament. Five other anti-Syrian figures also have been assassinated the past two years.

Many in Lebanon blame Syria for the killings, but Syria denies any involvement.

At the State Department, deputy spokesman Tom Casey said that Iran and Syria were the prime targets of the order, as well as one signed last month by Bush to block the assets of those who undermine stability in Iraq.

He said the Treasury Department was "actively looking at individuals and entities" to identify under the order, and that those designations were expected shortly.