The United States slapped new sanctions on Syrian President Bashar al-Assad's regime and its supporters on Friday, seeking to put further pressure on Damascus to end its bloody crackdown on opponents.
The State Department and US Treasury unveiled fresh measures that officials said were taken in response to the unfolding conflict in Syria, where 21,000 people have died in the past 17 months in the face of diplomatic stalemate.
The sanctions came with US Secretary of State Hillary Clinton set to fly to Istanbul for further talks on the Syrian crisis, with Washington focused on supporting the Syrian opposition seeking to topple Assad.
The United States has been forced to seek strategies outside the UN Security Council, as China and Russia have on three occasions vetoed resolutions backed by Western powers targeting Syria's regime.
In the first measure announced on Friday, the treasury denounced the Lebanon-based militant group Hezbollah for backing Assad and added it to a list of organizations under sanctions for their ties to the Syrian regime.
"This action highlights Hezbollah's activities within Syria and its integral role in the continued violence the Assad regime is inflicting on the Syrian population," the treasury said in a statement.
Washington already classes Hezbollah a "terrorist organization" and it is under US sanctions, but Friday's move explicitly ties the group to the violence in Syria, where Assad is attempting to put down a revolt.
"Hezbollah's extensive support to the Syrian government's violent suppression of the Syrian people exposes the true nature of this terrorist organization and its destabilizing presence in the region," said David Cohen, the Treasury's under secretary for terrorism and financial intelligence.
And in a second move against Assad's regime, the US State Department slapped sanctions on Syria's state oil company Sytrol for trading with Iran, under measures designed to starve both Assad and Tehran of much-needed revenue.
"This kind of trade allows Iran to continue developing its nuclear program while providing the Syrian government with resources to oppress its own people," State Department spokesman Patrick Ventrell said.
Citing Syria and Iran's "two-way trade in the energy sector, in which Syria sent 33,000 metric tons of gasoline to Iran in April, a deal said to be worth $36 million, the department said the measure should send "a stark message."
"Though these sanctions are a direct result of Syria's provision of gasoline to Iran, the United States views Iran's broader support for the Assad regime as completely unjustifiable," Ventrell said.
"Iran is actively advising, supplying, and assisting the Syrian security forces and regime-backed militias that are carrying out gross human rights abuses against the Syrian people."
Friday's sanctions followed measures last month against 29 members of the Syrian regime, including the ministers of finance, economy, justice and information, as well as the governor of the central bank.
While Washington had already frozen assets of around 100 regime members and barred US firms from doing business with them, the move by the treasury in July represented a significant ramping up of pressure on Assad's inner circle.
In addition to new sanctions, Clinton is expected to announce on Saturday in Istanbul an additional $5.5 million in humanitarian assistance for those fleeing the conflict in Syria, a US official said.