New York's main contract, light sweet crude for Mar delivery, was up 38 cents to USD 84.70 per barrel.
Brent North Sea crude for delivery in Apr advanced 21 cents to USD 101.85.
"Oil prices in general are still expected to be supported by protests in the Middle East," said Chen Xin Yi, commodities analyst for Barclays Capital.
Crude prices had risen over supply concerns in the volatile region as demonstrators in various Arab states drew inspiration from pro-democracy protests leading to the ouster of leaders in Tunisia and Egypt.
Unrest has followed in Iran, Yemen and Bahrain.
US president Barack Obama yesterday warned autocratic US allies they cannot crush the Middle East's youthful 'hunger' for change and offered 'moral support' to Iranian protesters defying a crackdown.