08:59 AM EDT, 06/23/2025 (MT Newswires) -- Oil prices rose early on Monday following the U.S. attack on Iranian nuclear facilities over the weekend, but fell off overnight highs as the market weighs the likelihood Iran will retaliate by blocking exports from the Persian Gulf.

West Texas Intermediate crude for August delivery was last seen up US$0.07 to US$73.91 per barrel, off an overnight peak of US$78.40, the highest in a year. August Brent crude was last seen up US$0.10 to US$77.11.

The United States bombed three Iranian uranium-enrichment facilities, joining Israel in striking at Tehran's nuclear program. President Donald Trump said the strikes using bunker-buster bombs on the Fordow, Natanz and Isfahan facilities "obliterated" the sites, though the extent of the damage and whether Iran was able to move stockpiles of enriched uranium prior to the attack remains unclear.

Traders are now awaiting Iran's response. The Islamic Republic has threatened to close the Strait of Hormuz to prevent tanker shipments from the Persian Gulf, which supplies around 20% of the world's oil demand, though its ability to block the passage is in doubt.

"While the situation remains very fluid, some Iranian officials have already made public threats to impede traffic in the Strait of Hormuz and have warned that Americans in the region could be targets of retaliatory action. Just as we were repeatedly told that only the US had capability to disable Fordow, security officials maintain that it would be difficult for Iran to fully close the Strait of Hormuz for an extended period due to the position of the US Navy's Fifth Fleet in Bahrain," Helima Croft, Head of Global Commodity Strategy and MENA Research at RBC Capital Markets, said in a Sunday note.

Oil prices have climbed 20% over the past month as the market added a risk premium to the commodity as Israel launched its war on Iran. But the conflict has yet to impede oil shipments and Israel has so far refrained from attacking the country's oil infrastructure.

"It's worth noting that the current geopolitical risk premium-now exceeding USD 10 per barrel-cannot be sustained for long without a tangible supply disruption. Absent that price gains may struggle to hold. The market now nervously awaits an Iranian response," Saxo Bank noted.