Oil prices climbed in early trading after U.S. forces attacked Iranian tankers and Tehran declared a new no-sail zone beyond the Strait of Hormuz, intensifying concerns over prolonged disruption to a critical energy shipping route. Brent crude opened up 0.8%, approaching the $97-per-barrel mark, while WTI crude traded near $92 a barrel.

The United States said it struck three Iranian tankers over the weekend, sinking one of them, in retaliation for Iran's ballistic missile attacks on U.S. naval vessels. In response, Iran's top security official announced that a new exclusion zone would be established outside the Strait of Hormuz within days, stretching from the U.S. blockade line into parts of the Persian Gulf. Iran also claimed to have hit three tankers, though that assertion has not been independently verified.

The renewed exchange of fire between Washington and Tehran, following a brief period of relative calm, drove crude prices sharply higher last week. With the Middle East conflict and the ongoing Russia-Iran war weighing on supply, Brent crude has gained nearly 60% year-to-date, while refined products such as diesel have posted even steeper increases.

U.S. Energy Secretary Chris Wright stated that the American military presence in the Gulf region will not be scaled back, which currently includes both a blockade on Iranian oil exports and measures to ensure safe passage for other commercial vessels. Wright noted last week that millions of barrels of crude transit the Strait of Hormuz daily.