WASHINGTON- Washington on Tuesday imposed sanctions on a China-based company it accused of acting on behalf of U.S.-blacklisted Iranian Mahan Air, the Treasury Department said, warning further sanctions could be imposed on those doing business with the airline.

The Treasury Department said in a statement that Shanghai Saint Logistics Limited acted as a general sales agent for Mahan Air, blacklisted by the United States in 2011 under counterterrorism authorities.

Tuesday's action freezes any U.S.-held assets of Shanghai Saint Logistics and generally prohibits Americans from doing business with the company.

"We will not hesitate to target those entities that continue to maintain commercial relationships with Mahan Air," Treasury Secretary Steven Mnuchin said in the statement.

The Treasury Department said in the statement Mahan Air is operating charter flights to Venezuela for Iranian technicians and technical equipment, using materials sourced from China, in support of Venezuelan President Nicolas Maduro.

A senior official in President Donald Trump's administration told Reuters last week the United States is considering measures it could take in response to Iran's shipment of fuel to crisis-stricken Venezuela.

(Reporting by Daphne Psaledakis and Lisa Lambert Editing by Chizu Nomiyama and Steve Orlofsky) ((lisa.lambert@thomsonreuters.com; +1 202 898 8328; Reuters Messaging: lisa.lambert.thomsonreuters.com@reuters.net))