Oil prices rose on Monday as supply shortages and political tensions in Eastern Europe and the Middle East put prices on track for their biggest monthly gain in nearly a year.
Brent crude, the benchmark, rose 66 cents, or 0.7 percent, to $90.69 a barrel by 1005 GMT. The March futures contract expires later on Monday.
US West Texas Intermediate crude rose 51 cents, or 0.6 percent, to $87.33 a barrel.
On Friday, the two benchmarks hit their highest level since October 2014.
On Sunday, the NATO chief said Europe should diversify its energy sources after Britain warned that Russia was very likely looking to invade Ukraine.
The market is also anticipating the situation in the Middle East, after the UAE said it had intercepted a ballistic missile launched by the Yemeni Houthi movement, while the Gulf state was hosting Israeli President Isaac Herzog in the first visit of its kind.
Analysts expected prices to remain high this week, with the OPEC + group, which includes the Organization of the Petroleum Exporting Countries and its allies, expected to maintain its existing policy of gradually increasing production.