The Organization of the Petroleum Exporting Countries doesn't meet until May 25, but U.S. shale-drilling pioneer Harold Hamm is certain the producer group will extend its six-month deal to restrain output.
"Well, there's been some downward pressure" on oil prices, with traders "wondering whether or not OPEC would keep the cuts in place. But I think it's a foregone conclusion those cuts will remain in place," the chairman and CEO of oil and gas exploration company Continental Resources told CNBC's "Power Lunch" on Tuesday.
OPEC members agreed last year to cut their combined production by 1.2 million barrels a day in the first half of 2017. Eleven other exporters including Russia contributed reductions of 558,000 barrels a day.
Oil prices sank more than 2 percent on Tuesday, as news that Russia had cut production and a survey indicating OPEC's output continues to decline was offset by rising supplies in the United States, Libya and Canada.
Hamm stressed that it takes a considerable amount of time to balance a market that has been oversupplied for more than two years, and the OPEC deal has only been in place since January. He noted that the summer driving season has not yet begun, making it more difficult to reduce stockpiles of crude oil and fuel.
"We're about two weeks from school being out, people on vacation. We'll see those inventories come down," Hamm said.
Asked about President Donald Trump's comment on Monday that he would consider raising the federal gasoline tax to pay for infrastructure improvements, Hamm said investments need to be made and "if that's what it takes, that's what it takes."
Hamm advised Trump on energy policy during his campaign.
Chevron CEO John Watson on Monday declined to support a gas tax hike, saying he would want the government to review how the current levy is being spent first.