DUBAI, United Arab Emirates: Lines have grown outside gas stations across Tehran in recent weeks as the United States has tightened its blockade and threatened more severe sanctions, with some people waiting for two hours or more to fill up. The uncertainty deepened on Tuesday, after US Treasury Secretary Scott Bessent vowed to fully sever the country from the global economy. In recent days, Iranian officials have spoken of a possible reduction in heavy gas subsidies as they seek to endure the tightening blockade.

Prices for food and other items are soaring, and there is a history of unrest, so any increase is being considered.

Iran has threatened to halt all oil exports across the Persian Gulf, as the United States is set to unveil crippling new sanctions on Monday. The upcoming US curbs aim to sever…