Brent fell $2.10, or 2.2%, to $93.54 a barrel, WTI slid $1.86, or 2.1%, to $87.69 a barrel.

Brent climbed 89 cents, or 0.9%, to $100.20 a barrel, WTI jumped 82 cents, or 0.9%, to $92.46 a barrel

Asked if there are guarantees that Gazprom will restart gas flows via Nord Stream 1, the Kremlin's Peskov said: "There are guarantees that, apart from technological problems caused by sanctions, nothing hinders the supplies."

A three-day halt of the Nord Stream pipeline -- a key source of natural gas for the European Union -- starts on Wednesday, and concerns are widespread that Moscow will find another excuse to clamp down on supplies, putting the region at the mercy of the weather.

Brent dropped 56 cents, or 0.5%, to $104.53 a barrel, WTI was at $96.86 a barrel, down 14 cents,

West Texas Intermediate was steady near $97 a barrel after jumping 4.2% in the week’s opening session amid concerns about the potential for supply interruptions in Libya

European natural gas prices on Monday plunged the most since March after Germany said its gas stores are filling up faster than planned.

Brent rose 65 cents, or 0.6%, to $101.64 a barrel, WTI was up $1.22, or 1.3%, at $94.28

Benchmark Dutch front-month futures fell as much as 16%, partly reversing last week’s jump of almost 40%.

Brent climbed 73 cents, or 0.73%, to $100.07 a barrel, WTI rose 78 cents, or 0.84%, to $92.93.