EMEA crude futures rallied in after-hours trading on Monday after President Trump said he would reinstate the US blockade on Iranian ships transiting the Strait of Hormuz, as Tehran and Washington battle to control the waterway.
Brent crude futures jumped by 5.7% to $80.31 per barrel, while Murban crude futures advanced by 6.8% to $75.77/bbl.
Gelber & Associates strategists said that crude should remain highly headline-sensitive, with further upside likely if shipping conditions deteriorate and a fast reversal possible if diplomatic talks restore confidence in Gulf transit.
Trump said on Monday that the US would reimpose its blockade of Iranian ships transiting the Hormuz and demanded a 20% reimbursement on all other cargo shipped via the strategic waterway.
"We are reinstating the Iranian blockade, so named because it is only stopping Iran's ships or customers from entering or leaving. All other countries will have fair and open use of the Strait," Trump said in a social media post on Truth Social.
Trump also said the US would don the role of "the guardian of the Hormuz Strait" and seek reimbursement of 20% on all cargo shipped, "... for any and all costs necessary to do the job of providing safety and security to this very volatile section of the world," according to his post.
The decision to reimpose the blockade added to bullish momentum after the US and Iran traded strikes over the weekend, including attacks on energy infrastructure, further straining a mid-June ceasefire that was expected to lead to a normalization of traffic through the Strait.
Iran's Islamic Revolutionary Guards Corps had earlier said that normal shipping through the strategic waterway could only resume if the US halted its military operations in the region, noting that continued American intervention risked broader disruption to global oil and gas markets.
The Persian Gulf Strait Authority, the Iranian authority overseeing navigation in the Hormuz, also said transit had been suspended following what it described as "illegal movements" by US military forces in the region.
The US military launched another wave of strikes Sunday against Iran after hitting 140 targets on Saturday, according to US Central Command's post on X.
Centcom said the US carried out its first combat use of unmanned surface vessels to strike Iran's Bandar Abbas Naval Base.
Saxo Bank strategists said that the hostilities risk derailing efforts to rebuild inventories, according to the International Energy Agency, while further reducing the prospects for a diplomatic resolution.
However, despite the attacks, the analysts said the relatively modest premium between front-month and deferred futures suggests the physical crude market remains orderly for now.
Meanwhile, Russian energy supplies have also been disrupted as Ukraine steps up attacks on Moscow's energy infrastructure.
Ukraine's Ministry of Defense said on Monday that it had struck 15 vessels linked to Russia's shadow fleet overnight, including oil tankers, dry cargo ships, a ferry and tugboats.
The latest strikes brought the number of vessels hit in the past eight days to 105, the ministry said in a social media post on X.
On Sunday, Ukrainian forces also hit seven Russian fuel tankers, five dry-cargo vessels and a batch of other ships in the Sea of Azov as Kyiv expands the scope of its maritime attacks in the area.