International oil prices have surged roughly 12% since Friday, climbing to their highest levels in about a month after renewed tensions between the United States and Iran heightened concerns over global crude supplies.

Brent crude traded close to $85 per barrel during Asian trading on Tuesday, while U.S. benchmark WTI crude approached $80 per barrel, extending gains after Monday’s sharp rally.

The latest advance came after military tensions escalated over the weekend and U.S. President Donald Trump announced the restoration of measures aimed at restricting Iranian oil exports, prompting investors to price in a higher geopolitical risk premium.

Markets are also increasingly worried about the Strait of Hormuz, the world’s most important oil shipping corridor. Expectations that tanker traffic would quickly normalize have faded as security concerns in the region intensified.

Adding to the uncertainty, Trump floated the idea of imposing a 20% charge on vessels using the Strait of Hormuz in return for U.S. naval protection. The proposal has drawn skepticism from market analysts, who say key details remain unclear and its implementation appears uncertain.

ING analysts estimate that such a fee could add around $32 million to the cost of transporting a typical supertanker carrying 2 million barrels of crude at $80 per barrel, increasing shipping costs by approximately $16 per barrel.

The renewed conflict has reversed much of the recent optimism in oil markets, with traders now closely monitoring developments in the Gulf for any further disruptions to global energy supplies.