Oil prices held above US$71 a barrel after hitting a two-month low last week, boosted by tensions over Iran's nuclear program and a cold snap in the US northeast.

Gains were kept in check by the strengthening US dollar, which made crude more expensive for investors holding other currencies.

By early afternoon in Europe, benchmark crude for March delivery was up 19 cents at US$71.38 a barrel in electronic trading on the New York Mercantile Exchange. Earlier in the session, it peaked at US$72.39.

On Friday, the contract plunged US$1.95 to settle at US$71.19.

Oil prices fell sharply late last week as concerns over swelling debt levels in Greece, Portugal and Spain and high unemployment in the US cast doubt over the global economic recovery.

Helping crude rebound were expectations of a spurt in demand for crude products like heating oil because of a cold spell in the US and tensions in the Middle East.

Still, analysts were skeptical about even the normally bullish blizzards.

"The US East Coast has been under a very severe snowstorm over the weekend, but given the shutdown of many of the transport systems, the storm should actually be negative to the total petroleum demand picture," said Olivier Jakob of Petromatrix in Switzerland.

Iran's president Mahmoud Ahmadinejad ordered Sunday his atomic agency to significantly enrich the country's stockpile of uranium, defying pressure from Western nations to halt its nuclear program.

"This is winter's last hurrah, while Iran's announcement also gives an excuse for investors to buy," said Victor Shum, an energy analyst with consultancy Purvin & Gertz in Singapore.

In other Nymex trading in March contracts, heating oil fell 0.08 cent to US$1.8740 a gallon, and gasoline was up 0.05 cent at US$1.8869 a gallon. Natural gas rose 10.4 cents to US$5.619 per 1,000 cubic feet.

In London, Brent crude was up 17 cents at US$69.76 on the ICE futures exchange.