By Ayenat Mersie
Brent crude futures rose by 64 cents to $78.71 per barrel by 11:38 a.m. EDT (1538 GMT). Earlier, the global benchmark hit a session high of $79.51.
U.S. crude futures were up 13 cents at $73.98, after hitting a high of $74.70.
Earlier in the session, prices had been within striking distance of the four-year highs, said Bob Yawger, director of energy futures at Mizuho.
They retreated, however, following a statement by U.S. Secretary of State Mike Pompeo that the United States would consider requests from some countries to be exempted from sanctions on Iranian oil that it will put in effect in November
"That basically took the wind out of the sails from the market," said Phil Flynn, analyst at Price Futures Group in Chicago.
"But it isn't unlike anything that they've said before. But it all depends on which countries they're talking about. Is it big buyers of Iranian crude? Is it India?...Is it temporary waivers?"
Last month, the United States said it wanted to reduce oil exports of fifth-biggest producer Iran to zero by November.
Still, supply concerns elsewhere were pushing Brent prices higher.
Hundreds of workers on Norwegian offshore oil and gas rigs went on strike on Tuesday after rejecting a proposed wage deal, leading to the shutdown of one Shell-operated oilfield. [nL8N1U56BO]
Libyan oil production fell to 527,000 barrels per day (bpd) from a high of 1.28 million bpd in February following recent oil port closures, the National Oil Corporation said on Monday.
"Working in the opposite direction of the Norwegian oil workers strike and the geopolitical situation" was the update on the Syncrude oil sands facility, said Yawger at Mizuho.
On Monday, Suncor Energy said its 360,000 bpd Syncrude facility would resume some production in July, earlier than expected, following an outage last month that disrupted total output.
The disruption had sent U.S. prices higher. The updated restart has muted U.S. crude's gains and helped widen the difference between the two benchmarks, said Yawger.
Meanwhile, Saudi Arabia, fellow members of the Organization of the Petroleum Exporting Countries and allies including Russia agreed last month to increase output to dampen price gains and offset global production losses.
But the market has grown concerned that if Saudi Arabia offsets Iranian losses, it will use up global spare capacity and leave markets vulnerable to further or unexpected production declines.
(Additional reporting by Aaron Sheldrick in Tokyo and Dmitry Zhdannikov in London; Editing by Marguerita Choy and Edmund Blair)
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)