West Texas Intermediate crude for March delivery$1.33, or 1.5%, to settle at $88.15 a barrel on the New York Mercantile Exchange. The U.S. benchmark tallied a 17.2% monthly rise, according to Dow Jones Market Data. Global benchmark March Brent crude rose $1.18, or 1.3%, at $91.21 a barrel on ICE Futures Europe, for a monthly rise of 17.3% as the contract expired at the end of the session. Brent and WTI both ended Monday at their highest levels since early October 2014 and with their strongest monthly percentage gains since February of 2021. April Brent, which is now the front-month contract, added 74 cents, or 0.8%, at $89.26 a barrel.

Russia has amassed around 100,000 troops near Ukraine border and taken other actions that have sparked fears an invasion of the neighboring country may be imminent. The U.S. and its allies have threatened searing sanctions against Moscow in the event of an attack. Russia has insisted that NATO rule out membership for Ukraine and has made other security demands that the U.S. and its allies have deemed nonstarters. At a United Nations Security Council meeting Monday, a Russian ambassador said that United States as “provoking escalation” of the situation by falsely charging Moscow with preparing to invade Ukraine, according to a report from The Washington Post.

The Organization of the Petroleum Exporting Countries and its Russian-led allies, a group known as OPEC+, will meet this week. OPEC+ has so far stuck to a timetable that has seen it add 400,000 barrels a day to output in monthly increments, though members have struggled to meet the increased quotas. “The only short-term solution for balancing the supply-short oil market will therefore need to come from OPEC+, and steered by Saudi Arabia, the producer with the largest spare capacity,” said Louise Dickson, senior oil markets analyst at Rystad Energy, in a note. “The group’s top producer could decide to add more ‘voluntary’ barrels outside the framework of the agreement to ease oil prices, a similar, but mirrored action from January 2021 when it surprised the market with an additional 1 million [barrel a day] cut,” Dickson said. “In short, Saudi Arabia can quickly and easily drum up spare capacity if it decides it is beneficial.”

January oil production from members of OPEC rose to 28.01 million barrels per day, up from December output of 27.8 million barrels per day, according to a Reuters survey released Monday.

“While the Saudi oil minister Prince Abdulaziz may call for time and patience at the Wednesday meeting, we do believe that the Kingdom’s calculations could change in the event that a conventional war breaks out on European soil and crude prices soar past the $100 [a barrel] mark,” analysts at RBC Capital Markets wrote in a research note dated Monday.

On Nymex, petroleum products ended on a mixed note as the February contracts expired at the end of the session. February gasoline added 0.5% to $2.554 a gallon, for a nearly 15% monthly rise. February heating oil  declined by 0.9% to $2.759 a gallon, up over 18% for the month.