The price of a barrel of Brent crude fell 0.5% to $88.48. U.S. gasoline prices edged 2 cents higher overnight to a national average of $4.04 per gallon, according to AAA.

The escalating rhetoric raises further doubt that any immediate deal can be reached over the strait, through which a fifth of the world’s oil flowed before the U.S. and Israel started attacking Iran on Feb. 28.

As the conflict extends into a sixth month, consumers around the world are once again facing the prospect of higher fuel prices and inflation.

Brent crude oil rises 0.3% to $87.99 a barrel, after surging 5% on Aug. 10 due to uncertainty over when the Strait of Hormuz may reopen.

The shuttling and transfers of barrels are providing a vital lifeline for global energy markets during the ongoing tensions in the region.

Trump narrowed the scope of relief from the Jones Act, requiring case-by-case reviews of individual voyages after pleas from shipbuilders that argue the policy hurts the domestic industry. 

The sweeping new demands from Trump are almost certain to be rejected by Iran and come after Tehran reiterated requests for reparations over the weekend.

Fewer owners are entering the Persian Gulf after attacks near Hormuz, tightening vessel supply and lifting benchmark earnings from about $200,000 before the war.

In the oil market, the price for a barrel of Brent crude rose 2% to $85.23. It had swung between $72 and $102 last month.

Foreign Minister Abbas Araghchi said a pact with Oman to establish a shipping route through the strait was “very close.” He ruled out direct talks with the U.S. for now.