Crude futures came under pressure on Friday but recovered from a sharp drop after President Donald Trump suggested in a tweet that OPEC is keeping oil prices artificially high.

@RealDonald Trump: Looks like OPEC is at it again. 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!

U.S. West Texas Intermediate crude oil prices were up 9 cents at $68.38 a barrel, after dropping as low as $67.50 after Trump's tweet.

International benchmark was at $74.07, up 29 cents at 2:29 p.m. ET, off a session low of $72.83.

Both benchmarks hit more than three-year highs this week, as falling U.S. crude stockpiles, geopolitical tension and concerns about supply disruptions in key oil-producing nations supported the market.

It was not immediately clear what sparked Trump's OPEC tweet, but Reuters reported earlier this week that Saudi Arabia would like oil prices to rise above $80 a barrel in order to support the stock market debut of the kingdom's oil giant Saudi Aramco.

That has stirred speculation that the Saudis could lobby against altering a production-cutting deal among two dozen oil producers, even as it nears its goal of shrinking oil stockpiles in developed nations to their five-year average.

"There's not much" Trump can do about the oil policy "except for talking about it," Daniel Yergin, Pulitzer Prize-winning writer and vice chair of IHS Markit, told CNBC's "Squawk Box" on Friday.

The agreement has helped boost prices from 12-year lows around $26 a barrel struck in 2016. The prolonged oil price rout heaped pressure on nations like Saudi Arabia that depend on oil revenues and sparked a wave of bankruptcies and layoffs across the American oil industry.