An expected rise in US oil production also weighed on prices, traders said.
US West Texas Intermediate (WTI) crude futures were at $61.32 a barrel at 0307 GMT, down 47 cents, or 0.8 percent, from their last settlement.
Brent crude futures fell 39 cents, or 0.6 percent, from their last close to $64.86 per barrel.
Wang Tao, Reuters technical commodity analyst, said Brent could fall into a range of $63.92 to $64.41 per barrel, as suggested by its wave pattern and a projection analysis.
Traders said the declines were driven by a recovery in the dollar, which potentially hits fuel demand as it makes greenback-denominated oil imports more expensive for countries using other currencies.
The dollar index, which measures the greenback against a basket of six major currencies, rose for a second day on Wednesday, moving further away from the three-year lows reached last week as traders shaved off some bearish bets against the US currency.
“The US dollar continues to find firmer footing,” said Stephen Innes, head of trading for Asia-Pacific at futures brokerage OANDA in Singapore.
Also pressuring prices is surging US production
“Bulging US production will weigh on prices,” said Singapore-based Phillip Futures in a note on Wednesday.
The next set of weekly US oil production data is due to be published by the Energy Information Administration (EIA) on Thursday after a one-day delay because of the President’s Day holiday on Monday.
That data will also include US inventory figures that are expected to show crude oil stockpiles rose 1.3 million barrels in the week to Feb. 16, according to a Reuters poll. Oil product stockpiles, including gasoline and distillate fuels, are all expected to decline.
Despite the rising US output, overall oil markets remain well supported due to healthy demand growth and supply restraint by the Organization of the Petroleum Exporting Countries (OPEC) that started last year to draw down excess global inventories.