Oil prices fell on April 20 after President Donald Trump criticized OPEC and said oil prices were artificially high, but they were still set for a weekly gain.

Brent crude oil futures LCOc1 were at $73.26 per barrel at 1139 GMT, down 52 cents from their last close.

West Texas Intermediate crude futures CLc1 were down 48 cents at $67.81 a barrel.

“Looks like OPEC is at it again,” Trump wrote in a post on Twitter.

“With record amounts of Oil all over the place, including the fully loaded ships at sea, Oil prices are artificially Very High! No good and will not be accepted!”

The United States cannot legally influence oil other than through releasing oil from its strategic reserves which it has done occasionally, most recently last year in the wake of Tropical Storm Harvey.

Both contracts had been trading in positive territory before Trump’s tweet.

Brent and WTI hit their highest levels since November 2014 on Thursday earlier this week, at $74.75 and $69.56 per barrel respectively, buoyed by a tightening market and higher demand.