Otunuga told Arab News that the price of oil has further room to rise this week.
Prices received a boost last week following President Donald Trump's announcement on May 8 that the USA would withdraw from the Iranian nuclear deal.
Fears of a trade war emerged in April when both sides engaged in a multi-billion dollar tit-for-tat over tariffs.
WTI light sweet oil was up 10 cents at USD70.80 a barrel, staying near last week's 4-year peak.
The West Texas Intermediate for June delivery rose 0.26 US dollar to settle at 70.96 dollars a barrel on the New York Mercantile Exchange, while Brent crude for July delivery rose 1.11 dollars to close at 78.23 dollars a barrel on the London ICE Futures Exchange.
Markets were dampened somewhat by a monthly market report from the Organization of Petroleum Exporting Countries that made few major revisions to its global expectations.
The Brent crude and U.S. oil elevated more than 3%, which hiked the oil prices.
In a report on Monday, OPEC said oil inventories in developed nations in March fell to 9 million barrels above the five-year average.
OPEC economists, however, expressed concern on spending on future projects in the industry. The IMF said it expects the price of oil to be in the $60 range on average through next year, which would represent a 20 percent increase over last year.
But booming output of USA shale producers - eager to cash in on a rally in oil prices since late past year - has proven a headache for combined efforts by both OPEC members and non-members to cut back production to combat a global oil glut.
Improving conditions for shale-derived oil and gas pushed total USA capacity past the 10m bbl/day mark in November last year, with the country expected to account for 1.5m bbl/day of the projected 1.7 m bbl/day supply growth from non-OPEC producers this year.
Nevertheless, it was "evident that uncertainties remain as to the forecast pace of growth of non-OPEC supply for the remainder of the year", the cartel cautioned. This compares to 340 million barrels above the average in January 2017.