International benchmark Brent crude increased to the highest in 2019 to date at $66.48 at 06.26 GMT on Monday, while American benchmark West Texas Intermediate (WTI) reached $55.97 at the same time.
Brent crude climbed to $64.81 at 12.05 GMT on Friday, while WTI has seen steady increases last week, with prices of $54.88 on Friday up from $52.25 last Monday.
Brent's rise has been sustained by the Organization of the Petroleum Exporting Countries (OPEC) and OPEC+ countries' supply cuts and the announcement of a higher-than-expected cut by Saudi Arabia.
U.S. sanctions on Venezuela and Iran are also pushing prices higher.
On Friday, crude prices gained more than 2 percent despite the weekly increase in the number of U.S. oil rigs by three to reach 857, according to data released by oilfield services company Baker Hughes.
Brent crude rose 2.7 percent to close at $66.31 per barrel on Friday, while WTI finished the day at $55.59 a barrel with 2.2 percent increase.
By Gulsen Cagatay
Anadolu Agency
energy@aa.com.tr