U.S. crude oil stockpiles climbed unexpectedly last week as net imports jumped, while gasoline stocks also posted a surprise build, the Energy Information Administration (EIA) said May 23.

Crude inventories rose 5.8 million barrels (bbl) in the week to May 18, compared with analysts' expectations for a decrease of 1.6 million bbl.

Inventories rose in part due to a sharp 1.4 million-bbl/d hike in net crude imports. Exports fell 818,000 bbl/d last week to 1.7 million bbl/d, after reaching a weekly record of 2.6 million bbl/d in the previous week.

"The large rise in crude oil inventories made for a bearish report, and it came as a result of decent sized drop in exports, along with a large increase in imports," said John Kilduff, a partner at Again Capital LLC in New York.

Oil prices were down on the news, pulling back from the broader rally on concerns about tightening supply around the world. The collapse of Venezuela's economy and increased U.S. sanctions is likely to hamper already depressed output from the OPEC member. Renewed U.S. sanctions following the cancellation of the Iran nuclear arms deal may also remove supply from the market.

Both of those factors, along with strong demand, have pushed oil to near-four-year highs. Brent crude recently touched $80 a barrel, though it was lower on May 23. As of 9:46 a.m. CDT (14:46 GMT), Brent was down $1.17/bbl at $78.40; U.S. crude lost 85 cents to $71.35/bbl.

Refinery crude runs fell by 7,000 bbl/d, EIA data showed. Refinery utilization rates rose by 0.7 percentage point to 91.8% of total capacity.

Gasoline stocks rose by 1.9 million bbl, compared with analysts' expectations in a Reuters poll for a 1.4 million-bbl drop.

Distillate stockpiles, which include diesel and heating oil, fell by 1 million bbl, vs. expectations for a 1.3 million-bbl drop, the EIA data showed.

Crude stocks at the Cushing, Okla., delivery hub fell by 1.1 million bbl, EIA said.