OIL prices rose on Friday, on track to end higher this week after two straight weeks of losses, after a top U.S. official expressed optimism over economic growth and as supply concerns lingered due to conflicts in the Middle East.

Brent crude futures gained 47 cents, or 0.5%, to $89.48 a barrel at 0640 GMT, and U.S. West Texas Intermediate crude futures rose by 44 cents, or 0.5%, to $84.01 a barrel.