As oil prices climb, Trump leans on OPEC to ramp up production "substantially"

WASHINGTON -- Hoping for what every president wants every summer -- lower gas prices -- President Donald Trump called on oil-producing countries Friday to "substantially" increase their production.

"Hope OPEC will increase output substantially. Need to keep prices down!" the president tweeted.

The request came after OPEC announced that it would increase oil supplies -- but would not say by how much.

OPEC's lack of clarity led to a sharp rise in oil prices Friday, with crude futures rising by more than 2%.

Earlier this week, Trump criticized OPEC in a tweet that said oil prices are already too high and the cartel is "at it again."

OPEC officials blamed U.S. sanctions on oil producing states like Iran and Russia.

Iran's OPEC governor, Hossein Kazempour Ardebili, told Reuters: "This is business, Mr. President -- we thought you knew it."

WPXI