In the previous session, U.S. crude lost 5 percent of its value as the market began to price in the possibility of a deal with Iran.

Benchmark Brent crude oil was down 35 cents at $ 56.06 a barrel.

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Iran and six world powers (USA, China, Russia, Germany, France and Britain) tried to break an impasse in nuclear negotiations on Sunday ahead of a deadline to find a deal by Tuesday which could add oil to an already oversupplied market if sanctions against Tehran are lifted.