The United States hit Iran's oil and petrochemicals sectors with new sanctions Friday in response to Tehran's October 1 attack against Israel, designating dozens of new companies and firms.
The Treasury Department said it was going after Iran's so-called "shadow fleet" of ships involved in selling Iranian oil in circumvention of existing sanctions, designating 10 companies and 17 vessels as "blocked property" over their involvement in shipments of Iranian petroleum and petrochemical products.
The State Department also announced it was slapping sanctions on six other firms and six ships for "knowingly engaging in a significant transaction for the purchase, acquisition, sale, transport, or marketing of petroleum or petroleum products from Iran."
"Today's sanctions target Iranian efforts to channel revenues from its energy industry to finance deadly and disruptive activity - including development of its nuclear program, the proliferation of ballistic missiles and unmanned aerial vehicles," Treasury Secretary Janet Yellen said in a statement.
The sanctions form part of the US response to Iran's attack, in which it launched some 200 ballistic missiles against Israel in retaliation for the killing of Hezbollah's Hassan Nasrallah, and Hamas leader Ismail Haniyeh.
Israel has said its response to Iran's second direct attack against its territory this year would be "deadly, precise, and surprising".
US President Joe Biden told reporters last week that Israel should consider "other alternatives than striking oil fields," amid reports it was planning to do so.
His national security advisor Jake Sullivan said Friday that sanctions had been announced after the president had consulted with America's allies and partners.
"These measures will help further deny Iran financial resources used to support its missile programs and provide support for terrorist groups that threaten the United States, its allies, and partners," Sullivan said in a statement.
Secretary of State Antony Blinken said Washington had made clear after the October 1 attack that Tehran would face consequences. The US has backed its ally Israel throughout the war in Gaza, the invasion of Lebanon and the general escalation in the region, providing billions of dollars worth of weapons.
"To that end, we are taking steps today to disrupt the flow of revenue the Iranian regime uses to fund its nuclear program and missile development, support terrorist proxies and partners, and perpetuate conflict throughout the Middle East," he said in a statement.