Brent crude oil futures were at 74.02 per barrel, up 16 cents, or 0.2 percent, from their last close, but were some way below the November-2014 high of $75.47 a barrel reached the previous day.
June ICE Brent futures were 58 cents higher than Wednesday's settle at $74.58/b while the NYMEX June light sweet crude contract climbed 41 cents to $68.46/b.
A top adviser to Iran's supreme leader said Tehran would not accept any change to its nuclear deal, as Western signatories prepare a new package in the hope of persuading U.S. President Donald Trump to stick with the accord.
USA crude stocks rose last week as refineries cut output, while gasoline stocks increased and distillate inventories fell, the Energy Information Administration said on Wednesday.
Oil rose on Thursday, supported by expectations of renewed United States sanctions on Iran, declining output in Venezuela and continuing strong demand.
The geopolitical tension has prompted analysts to speculate that oil could easily exceed US$80 a barrel if President Trump refuses to sign the nuclear deal by May 12.
The oil price has risen by 15% in the last four weeks, thanks to expectations that the USA will re-impose sanctions on Iran, a major oil producer and member of oil cartel Opec.
U.S. crude oil inventories rose by 2.2-million barrels in the week to April 20 to 429.74-million barrels. These were supported by a further decline in Venezuela's crude oil production.
The supply side-driven increase in crude oil prices is likely to spur a major differentiation in emerging markets' performance, hurting large net oil importers with weak economic fundamentals, possibly by more than it benefits large net oil exporters, the brokerage said. That's nearly 10 million barrels above the five-year average.
With most USA producers now profitable at prices under $40 per barrel and the forward curve significantly higher than that for years to come, American drillers will likely continue to increase output as they are able to hedge themselves profitably for the foreseeable future.
"The builds in crude oil and gasoline inventories are obviously negative, but soaring crude oil and gasoline exports cut against those data points", said John Kilduff, partner at energy hedge fund Again Capital LLC in NY.
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".
The soaring US output has made WTI crude around $6 per barrel cheaper than Brent, the worldwide benchmark for oil prices.
Kuwait orders Philippine ambassador to leave in one week
The Philippine government and Villa on Tuesday apologized to Kuwait after the latter lodged a diplomatic protest over the rescue. Duterte said about 500,000 Filipinos were working in Kuwait as of February 2018, many of whom were employed as house servants.