International benchmark Brent crude traded at $63.83 per barrel at 06.30 GMT on Monday.
American benchmark West Texas Intermediate (WTI) reached $58.69 barrel at the same time.
Last Friday, WTI crude reached its highest level since June 30, 2015. The price of the American benchmark climbed as high as $59.03 per barrel with a 1.1 percent daily gain, according to official data.
In addition, the number of oil rigs in the U.S. increased by nine this week, according to data from oilfield services company Baker Hughes on Wednesday.
The oil rig count, which is an indication of short-term changes in the country's crude oil production, reached 747 for the week ending Nov. 22.
Expectations that OPEC producers and Russia will extend their production cut agreement beyond March 2018 have been positively affecting crude oil prices for the past three weeks.
On Thursday this week, Vienna will host the 173rd (Ordinary) OPEC Meeting and the third OPEC and non-OPEC Ministerial Meeting in which participants are expected to discuss the extension decision.
By Gulsen Cagatay
Anadolu Agency
energy@aa.com.tr