"The cold weather continues to come into play here with a fall in distillate supplies," said Desmond Chua, an analyst at CMC Markets in Singapore.

"Investors seem to like the certainty and confidence of new Fed Chief Janet Yellen," he added.

New York's main contract, West Texas Intermediate for March, was up 42 cents at $100.36 in midday Asian trading, while Brent North Sea crude was eight cents higher at $108.76.

Yellen, in her first public comments as Fed chair after taking the helm of the US central bank on February 1, stressed little deviation from the current strategy of the policy-setting Federal Open Market Committee.

"I expect a great deal of continuity in the FOMC's approach to monetary policy," she told the Financial Services Committee of the US House of Representatives on Tuesday.