The US plans to announce new sanctions as soon as Thursday targeting Iranian oil exports, two people familiar with the matter said, as the Biden administration seeks to sever a crucial financial lifeline and put new pressure on Tehran to return to compliance with the 2015 nuclear deal.

The sanctions will focus on entities facilitating the oil trade, and will be part of broader plan to step up sanctions on the regime in the coming weeks, said one of the people, who asked not to be identified discussing private deliberations.

Iran has stepped up oil exports despite a crushing sanctions regime that went back into effect after former President Donald Trump quit the multinational Iran nuclear deal in 2018. Those exports have recently fallen from a peak of 1 million barrels a day as Tehran faces increased competition from Russia, which is eager to sell at discounted prices to counter a separate array of sanctions imposed over the war in Ukraine. 

Spokespeople at the National Security Council and the departments of State and Treasury didn’t immediately respond to requests for comment.

The Biden administration started talks to return to the nuclear agreement shortly after coming into office. But those talks have run aground over Iran’s insistence that President Joe Biden guarantee any future US administration won’t quit the deal as Trump did -- something US officials say he can’t do.

A return to the deal could bring relief to Iran’s lucrative oil trade, but most analysts doubt it will be restored before the US midterm elections in November, if then, and Iran has found no shortage of buyers -- mainly from China -- willing to buy its oil in the meantime.