Oil rose more than 1 per cent on Monday to near 7-year highs hit in the previous session, while supply concerns and political tensions in Eastern Europe and the Middle East put prices on track for their biggest monthly gain in almost a year.
Brent crude rose $1.07, or 1.2 per cent, to $91.10 a barrel at 0325 GMT, after adding 69 cents on Friday. The front-month contract for March delivery expires later in the day.
The most-active Brent contract, for April delivery, was trading at $89.51, up 99 cents or 1.1 per cent.
US West Texas Intermediate crude added $1.07, or 1.2 per cent, to $87.89 a barrel, having gained 21 cents on Friday.
