By Amanda Cooper
Brent crude oil futures were last up 60 cents at $74.60 a barrel at 0930 GMT, while U.S. West Texas Intermediate (WTI) crude futures were up 43 cents at $68.48 per barrel.
The oil price has risen by 15 percent in the last four weeks thanks to expectations that the United States will re-impose sanctions against Iran, a major oil producer and member of the Organization of the Petroleum Exporting Countries (OPEC).
French President Emmanuel Macron said on Wednesday that he expected U.S. President Donald Trump to pull out of a deal with Iran reached in 2015, in which Iran suspended its nuclear programme in return for Western powers lifting crippling sanctions.
Trump will decide by May 12 whether to restore U.S. sanctions on Tehran, which would likely result in a reduction of its oil exports.
"The price rise is due to growing expectations of new U.S. sanctions ... which would doubtless reduce the oil supply from Iran," Commerzbank said in a note.
"French President Macron appears to have little hope that he would be able to persuade US President Trump to remain in the nuclear agreement ... Since the market is already tight because of the high production outages in Venezuela and the production cuts implemented by OPEC and Russia, any further reduction of supply weighs all the more heavily," the bank said.
Venezuela's crude production has fallen from almost 2.5 million barrels per day (bpd) in early 2016 to around 1.5 million bpd due to political and economic crisis.
Venezuela's plunging output and looming U.S. sanctions against Iran come against a backdrop of strong demand, especially in Asia, the world's biggest oil consuming region.
However, not all market indicators point towards tighter supplies.
U.S. crude oil inventories rose by 2.2 million barrels in the week to April 20, to 429.74 million barrels.
U.S. crude production rose by 46,000 bpd on the previous week, to 10.59 bpd.
Soaring U.S. output has made WTI crude around $6 per barrel cheaper than Brent and drawn exports to record highs.
Dutch bank ING said "the wide discount for WTI to Brent saw exports rising 582,000 bpd week-on-week to a record high of 2.33 million bpd."
With U.S. output and exports surging, some analysts warn that the 20-percent climb in Brent prices since February is starting to look overdone.
"The market does look a little toppish," said Greg McKenna, chief market strategist at futures brokerage AxiTrader.
(Additional reporting by Henning Gloystein in SINGAPORE; Editing by Keith Weir)
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)