Oil prices were firmer on Friday after hitting fresh three-year highs in the previous session, as weakness in the dollar continued to underpin prices with crude on track for a weekly gain.
U.S. West Texas Intermediate (WTI) crude futures ended Friday's trade up 63 cents, or 1 percent, at $66.14 a barrel, the best settle since Dec. 4, 2014. On Thursday, they reached their highest intraday level since December 2014, at $66.66 per barrel.
Brent crude futures rose 29 cents to $70.71 per barrel at 2:21 p.m. ET. On Thursday, the contract climbed to as high as $71.28 per barrel, also its highest since December 2014.
"One has to question if this rally is sustainable. Downside protection is going to be warranted," said Brian LaRose, technical analyst at United-ICAP.
Both contracts posted weekly gains after support from a weakening dollar, which on Friday hit new three-year lows against a basket of other leading currencies.