Brent and U.S. crude have both gained more than 6% this week after the Organization of the Petroleum Exporting Countries (OPEC) and allies including Russia — a group known as OPEC+ — on Sunday pledged surprise production cuts.

Crude dipped on Thursday, however, as weak U.S. economic data raised concern over economic growth. The U.S. services sector slowed more than expected in March and U.S. job openings in February dropped to their lowest in nearly two years.

"The oil market's bullish momentum may have paused, but upside potential remains given the tightening supply backdrop," said Stephen Brennock of oil broker PVM.

Brent crude fell 17 cents, or 0.2%, to $84.82 a barrel by 1032 GMT. West Texas Intermediate U.S. crude dipped by 16 cents, or 0.2%, to $80.45. There is no trading on Friday because of the Good Friday holiday.

The U.S. dollar index strengthened on Thursday, rebounding from a recent two-month-low. A stronger dollar makes crude becomes more expensive for holders of other currencies and tends to reflect greater risk aversion among investors.

"A slowdown in the U.S. economic outlook is weighing on the upside on U.S. oil prices, however we continue to expect a further uptick in oil prices to the end of the quarter," National Australia Bank analysts Baden Moore and Adam Skelton wrote in a note.

Also underpinning the market was this week's snapshot of U.S. supply, which showed crude inventories fell by a more than expected 3.7 million barrels while gasoline and distillate inventories also declined, hinting at rising demand.