(CNN) - President Barack Obama Wednesday imposed tough sanctions against Syrian President Bashar al-Assad and six other senior Syrian officials in an effort to stop the regime's fierce crackdown on protests, the U.S. Treasury Department said.
The sanctions also target two top Iranian officials whose unit was a "conduit for Iranian material support" to Syrian intelligence, according to a copy of the executive order issued by the White House.
Obama signed the order Wednesday, a move a senior administration official described as a "decisive step to increase pressure" on the Syrian government to end violence, intimidation and pressure "and begin transitioning to a democratic" process.
Condemning Syria's use of violence and intimidation against its people, the official said al-Assad "must put an end to the attacks on protesters, mass arrests and harassment" of citizens expressing rights and "must begin to introduce change."
The Syrian government has launched a clampdown on peaceful demonstrators since mid-March. The United Nations last week said as many as 850 people have died in the protests, and there have been thousands of arrests.
Along with al-Assad, the other senior Syrian officials are Vice President Farouk al-Shara, Prime Minister Adel Safar, Interior Minister Mohammad Ibrahim al-Shaar, Defense Minister Ali Habib Mahmoud, head of Syrian Military Intelligence Abdul Fatah Qudsiya and Political Security Directorate chief Mohammed Dib Zaitoun.
"As a result of this action, any property in the United States or in the possession or control of U.S. persons in which the individuals listed in the Annex have an interest is blocked, and U.S. persons are generally prohibited from engaging in transactions with them," the Treasury Department said in a statement detailing the steps.
The senior administration official said it's too early to estimate how much will be frozen.FULL STORY
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