Oil prices marginally gave up gains made on Monday as the US dollar hovered close to a four-month high.

Traders and market watchers continue to express fears of renewed US sanctions against Iran.

US West Texas Intermediate crude for June delivery increased two cents to reach $68.59 a barrel, while London Brent crude for new July delivery rose one cent to trade at $74.70, according to Reuters.

The June contract expired on Monday after settling up 53 cents at $75.17.

Prices steadied after witnessing an increase on Monday, propelled by Israeli Prime Minister Benjamin Netanyahu’s display of ‘evidence’ of a secret Iranian nuclear weapons programme.

US President Donald Trump has given Britain, France and Germany time until 12 May to issues pertaining to the 2015 nuclear deal reached with Iran.

“There are worries that Iran’s oil exports could fall by about one million barrels per day from current levels.”

Mitsubishi UFJ Research and Consulting senior economist Tomomichi Akuta was quoted by the news agency as saying: “There are worries that Iran’s oil exports could fall by about one million barrels per day from current levels.

“If that happened, Brent prices could jump to near $90 (a barrel).”

Even after the slight decline, oil prices remained close to more than the recent three-year high.

A Reuters survey has indicated that oil production from the organisation of the Petroleum Exporting Countries (OPEC) has reached the lowest levels in a year.

The slump in production is a result of declining output in Venezuela, caused by political and economic turmoil, and lower shipments from African producers.

However, oil prices face threat from rising US production.

Based on data released by the Energy Information Administration (EIA), US crude output soared 260,000 barrels per day to 10.26 million barrels per day in February this year.