Oil rises as investors assess attacks on Russian energy facilities

 Oil prices rose on Monday as investors assessed the impact of Ukrainian drone attacks on Russian refineries and U.S. President Donald Trump pressing NATO nations to halt Russian oil purchases.

Brent crude futures rose 41 cents, or 0.61%, to $67.40 a barrel by 11:43 a.m. EDT (1543 GMT) while U.S. West Texas Intermediate crude was at $63.25 a barrel, up 56 cents or 0.89%.

Attacks on Russian oil infrastructure and mounting pressure from Trump on buyers of Russian crude were boosting oil prices on Monday, said Phil Flynn, senior analyst with Price Futures Group.

"Behind the scenes there are a lot of concerns around heavy oil and tight diesel supplies, keeping the market supported," Flynn added.

Ukraine launched a large attack with at least 361 drones targeting Russia overnight, sparking a brief fire at the vast Kirishi oil refinery in Russia's northwest, Russian officials said on Sunday.

Both crude contracts gained more than 1% last week as Ukraine stepped up attacks on Russian oil infrastructure, including the largest oil exporting terminal, Primorsk.

Primorsk has a capacity to load about 1 million barrels per day of crude, while the Kirishi refinery processes about 355,000 bpd of Russian crude, equal to 6.4% of the country's total.