The Bush administration acted Wednesday to financially clamp down on Syria's military intelligence chief, Assef Shawkat.

The Treasury Department ordered U.S. banks to block any assets found in the United States belonging to Shawkat. Americans also are barred from doing business with him.

The department alleged that Shawkat has played a role in furthering Syria's "support for terrorism and interference in the sovereignty of Lebanon."

It marked the United States' latest action to turn up the heat on Syria.

In June, the department moved to block the assets of Syria's interior minister, Ghazi Kanaan, and its chief of military intelligence for Lebanon, Rustum Ghazali.

The power for the department to take the action stems from a May, 11, 2004, executive order by President Bush.

The department alleged that Shawkat had dealings with Hezbollah, the Popular Front for the Liberation of Palestine-General Command, Hamas and Palestinian Islamic Jihad — groups the United States has designated as global terrorists.

Shawkat met with officials from these groups and "discussed coordination and cooperation" among them, the department alleged.

The department also pointed out that Shawkat has "assess to the highest levels of the Syrian power structure" because he is the brother-in-law to and close confident of Syrian President Bashar Assad.

Syria is on the State Department's list of countries and organizations accused of supporting terrorism. The United States continues to have diplomatic relations with Syria, but tensions have increased.

Syria has come under intense international pressure since a truck bomb killed Lebanese leader Rafik Hariri in Beirut on Feb. 14. Syrian officials have been linked to the killings though they deny any involvement. The United States has demanded that Syria improve cooperation with a U.N. investigation of the assassination.

Syria has said that all of its military forces left Lebanon last April. For some three decades, Syria's military was the dominant political and military force there.