- Brent crude and WTI prices climbed Monday after President Donald Trump rejected Iran’s latest proposal to reopen the Strait of Hormuz, reviving concerns about global oil supplies and keeping energy markets focused on the conflict.
Oil prices moved sharply higher on Monday, Sept. 28, after US President Donald Trump rejected an Iranian proposal aimed at resolving the conflict and reopening the Strait of Hormuz. Brent crude futures rose more than 3% in early trading, reaching $107.75 a barrel, while US West Texas Intermediate (WTI) crude climbed to $94.55, according to Reuters.
The move reversed some of the relief seen late last week, when crude prices declined as investors assessed the possibility of a diplomatic agreement between Washington and Tehran. The latest price action follows an Iranian proposal presented at the United Nations General Assembly last week. Iran said the proposal had been transmitted to the US through Qatari mediators and was intended to provide a path toward reopening the Strait of Hormuz.
Trump said over the weekend that he rejected the proposal, although he also indicated that US negotiators could continue talks with Iran this week. The renewed uncertainty is particularly important for oil markets because the Strait of Hormuz remains a critical route for global energy shipments.
Strait of Hormuz Keeps Oil Market on Edge
The latest move comes after several weeks of extreme volatility in crude markets. Brent gained about 0.4% last week, while WTI fell roughly 7.9%, according to Reuters, as traders weighed improving regional oil flows against the possibility of further disruptions.
Preliminary Kpler data showed crude exports from key Middle Eastern producers recovering to 12.8 million barrels per day in September, the highest level since the conflict began in February. Shipments through the Strait of Hormuz were expected to reach approximately 7.4 million barrels per day during the month.
However, regional exports remain below pre-conflict levels. Kpler data showed September exports were still about 6 million barrels per day below the 18.8 million barrels per day recorded in February. The recovery has provided some relief to the physical oil market, but the diplomatic uncertainty means traders continue to attach a geopolitical premium to crude.
Recent oil-market coverage showed how quickly prices can respond when expectations for Middle Eastern supply change. Saudi Arabia has also been working to restore alternative export routes after attacks disrupted its East-West pipeline.
The pipeline is important because it allows Saudi Arabia to move crude toward the Red Sea and reduce its reliance on the Strait of Hormuz. Reuters reported that Saudi Arabia has resumed operations, although restoring the system to its full capacity could take several weeks because three pumping stations were damaged.
For oil traders, the combination of recovering exports and continuing security risks creates a market where prices can move sharply in response to diplomatic or military developments.
Diesel Shortages Add Another Oil-Market Risk
Crude is not the only part of the energy market under pressure. Diesel prices have reached record levels as disruptions to Middle Eastern supply routes and attacks on Russian refining infrastructure have reduced available refined products. Reuters reported that US retail diesel prices have risen above $6 a gallon, while European diesel futures have more than doubled from their levels at the start of 2026.
The administration is also considering restrictions on US diesel exports. Trump said Sunday that he was still looking seriously at a potential diesel export ban, arguing that restricting overseas shipments could increase domestic availability. The US has recently become an important supplier to international diesel markets, with exports reaching a weekly record near 2 million barrels per day last month.
A restriction could have competing effects. It could increase the amount of diesel available domestically, but reducing US exports would also remove supply from international markets that are already experiencing tight conditions. S&P Global has reported that the administration is examining both full and partial restrictions.
The diesel market therefore adds another layer of uncertainty for crude and refined-product prices. For now, the direction of oil prices remains closely tied to developments involving Iran and the Strait of Hormuz. A credible agreement that restores normal shipping could reduce the supply-risk premium, while renewed attacks or a further deterioration in negotiations could increase concerns about physical shortages.
The immediate market reaction on Monday shows that traders have not treated last week's diplomatic discussions as a resolution. Brent's move back above $107 and WTI's rise toward $95 reflect renewed uncertainty over how quickly normal energy flows can be restored.