The US government has begun drawing up sanctions against Syrian President Bashar Assad and his inner circle, officials said, as the White House condemned the increasingly violent crackdown against anti-government protesters in which more than 300 people have been killed.
An official said discussions about the severity and scope of possible sanctions were under way, but would probably involve asset freezes and travel bans against Assad, members of his family and senior regime officials.
Syria is already subject to numerous penalties as it is deemed a "state sponsor of terrorism" by the US State Department. The sanctions now being considered would target specific individuals accused of ordering or committing human rights abuses, the official said.
Similar sanctions were crafted for Libyan leader Muammar Gaddafi, his family and top aides. But the model for the Syria sanctions is likely to be the penalties put in place against senior Iranian officials for human rights abuses in the aftermath of disputed elections, the official said.
The official acknowledged that calls for sanctions have been growing as Assad's crackdown on protesters intensifies. On Monday, troops backed by tanks and snipers stormed the southern city of Daraa, according to witnesses.
At the White House, National Security Council spokesman Tommy Vietor deplored the latest developments and said sanctions against the Assad regime were a possible response.
His comments marked the first time a US official has said publicly that sanctions were an option. Since President Barack Obama took office in 2009, his administration had tried to engage Assad's government and encourage reforms.
"The brutal violence used by the government of Syria against its people is completely deplorable and we condemn it in the strongest possible terms," Mr Vietor said.
"The United States is pursuing a range of possible policy options, including targeted sanctions, to respond to the crackdown and make clear that this behaviour is unacceptable."