Geopolitical tensions in Eastern Europe and capacity issues among members of the Organization of Petroleum Exporting Countries and OPEC+ allies led by Russia are sending the prices up, writes Reuters.

A barrel of European benchmark oil Brent costs USD 91.10 Monday morning against USD 90.66 Friday afternoon. At the same time, the US counterpart West Texas Intermediate trades at USD 87.84 against USD 87.74 Friday afternoon.

"Underlying anxiety about global supply shortages, coupled with ongoing geopolitical risks, have caused the market to start the week on a strong note," says analyst at Fujitomi Securities Co Ltd. Toshitaka Tazawa to the news agency.

With respect to the geopolitical tensions between Russia and Ukraine, NATO has called on Europe to diversify its energy suppliers.

On the supply side, OPEC+ has gradually increased output by 400,000 barrels of crude a day since August. However, some member nations are having difficulties meeting production targets due to capacity issue.

"With an expectation that OPEC+ will keep the existing policy of gradual increase of production, oil prices will likely stay on a bullish sentiment this week," adds Toshitaka Tazawa.