Oil prices climbed further on Monday as markets weighed the impact of Ukrainian drone strikes on Russian refineries, which threaten to disrupt crude and fuel exports, while also tracking signs of rising United States fuel demand.

Brent crude futures were up 36 cents, or 0.5 per cent, at $67.35 a barrel, while U.S. West Texas Intermediate gained 36 cents, or 0.6 per cent, to $63.05.

Both benchmarks rose over 1 per cent last week as Ukraine intensified strikes on Russian oil facilities, targeting the Primorsk export terminal, the country’s largest, and the Kirishinefteorgsintez refinery, one of Russia’s two biggest plants, according to Reuters.

“The attack suggests a growing willingness to disrupt international oil markets, which has the potential to add upside pressure on oil prices,” JPMorgan analysts led by Natasha Kaneva said in a note, referring to the attack on Primorsk.

Primorsk, Russia’s largest western port, can load around 1 million barrels per day m of crude, making it a critical hub for the country’s oil exports.

The Kirishi refinery, run by Surgutneftegaz, processes roughly 17.7 million metric tons annually — about 355,000 bpd — representing 6.4 per cent of Russia’s total refining capacity.

“If we are seeing a strategic shift by Ukraine towards Russian oil exporting infrastructure – that brings upside risks to forecasts,” IG markets analyst Tony Sycamore said.

This comes despite lingering oversupply worries as OPEC+ prepares to boost output.

In Russia’s Bashkortostan region, a local oil company will keep production steady despite a drone strike on Saturday, Governor Radiy Khabirov said.

Meanwhile, pressure on Moscow is intensifying after U.S. President Donald Trump reiterated on Sunday his readiness to impose sanctions, stressing that Europe must match Washington’s stance.