The United States is revoking a general licence that authorised the sale of Iranian oil, a US official said on Tuesday, warning that Iran would face consequences after attacks on commercial tankers in and near the Strait of Hormuz.
The announcement sent oil prices up more than 3% as investors weighed the risk of further disruption to energy supplies through one of the world's busiest shipping routes.
The US official described Iran's actions in the Strait of Hormuz as "wholly unacceptable" but said negotiators were continuing to work in good faith toward a final agreement with Tehran despite the latest escalation.
The move followed reports that three tankers had been struck by unknown projectiles in and near the Strait of Hormuz in recent days, according to the British military's United Kingdom Maritime Trade Operations (UKMTO). There was no immediate comment from Tehran, and no group claimed responsibility for the attacks.
A second US official, speaking on condition of anonymity, said initial indications suggested Iran had fired at three commercial vessels.
The incidents threaten to undermine a fragile diplomatic understanding between Washington and Tehran, raising concerns that further retaliation could derail negotiations on a broader agreement.
The two sides had been working toward a deal that would place limits on Iran's nuclear programme while providing relief from some US sanctions, including restrictions on Iranian oil exports.
The Strait of Hormuz, which lies between Iran and Oman, is one of the world's most important energy chokepoints, handling about one-fifth of global oil consumption as well as significant volumes of liquefied natural gas shipments each day.
Any prolonged disruption to shipping through the waterway could drive up global energy prices and add to inflationary pressures for consumers and governments.
Oil exports remain a major source of revenue for Iran, generating billions of dollars in hard currency despite years of US sanctions. Much of Iran's crude exports have continued to flow to China in recent years, making oil sales a key pillar of the country's economy.
The latest US move is expected to increase pressure on Iran's finances by further restricting its ability to export oil.
