The same day, the State Department labeled as a terrorist Mohammad al-Golani, for being the leader of the al-Nusra Front. The group is one of the most effective forces fighting Syrian President Bashar al-Assad, but also pledged allegiance to Al Qaeda leader Ayman al-Zawahri last month.
The dual designations underline the quandary facing the United States, which favors Assad's overthrow but fears increasingly radical elements within the opposition.
Washington has imposed sanctions on Syria since the beginning of the increasingly violent two-year civil war in the country that has killed an estimated 80,000 people.
The US Treasury Department said the government-owned airline, Syrian Arab Airlines, helped Iran's Islamic Revolutionary Guards ship illegal cargo - including rockets, anti-aircraft guns and ammunition - to aid the Syrian government.
The United States also accused the privately held Al-Dunya Television of assisting Assad's propaganda by airing forced confessions. Al-Dunya also helped the government disseminate fake weapons busts and arrest people it had interviewed, according to Treasury.
Treasury also blacklisted, or designated, four Syrian officials: the ministers of defense, health, industry, and justice, as part of its broader steps to stymie the government's activities. The defense minister, Fahed Jaseem al-Freij, has been in charge of Syria's armed forces during air strikes and executions of civilians, according to the US government.
"Treasury will continue to use all of the tools at our disposal to expose and disrupt the financial networks of those responsible for the Syrian government's egregious campaign to suppress its people," Treasury Undersecretary for Terrorism and Financial Intelligence David Cohen said in a statement.
US President Barack Obama on Thursday said he may use a range of diplomatic and military options against Assad's government if he gets conclusive proof it used chemical weapons in the country's civil war.
The Obama administration has so far avoided arming opposition forces for fear weapons could find their way to Islamist hardliners who might use them against Western targets.
The new Treasury sanctions forbid US citizens from any financial dealing with the officials and companies, and also freeze their assets within the United States. Although the officials are unlikely to hold money in US banks, many foreign banks are also reluctant to deal with companies and people that have been blacklisted by the United States.
In 2011, the United States froze all Syrian assets in the United States and barred US citizens from making new investments or exporting services to Syria. It has also imposed sanctions on Syria's government, central bank, oil companies and more than 100 other individuals.
The State Department labeled Nusra a terrorist organization back in December.
"By opting for the use of force against its own people, the Assad regime has created the circumstances that attract the violent extremists, who seek to exploit civil strife for their own purposes," the State Department said in a statement. "The sooner the political transition to a post-Assad Syria begins, the better it will be for the Syrian people and the region."