Oil prices fell on Friday, but were set for weekly gains ahead of the OPEC+ meeting which kicked off Friday in Vienna.

The Organization of the Petroleum Exporting Countries (OPEC) and allies including Russia - a grouping known as OPEC+ - agreed on Thursday to more output cuts to avert oversupply as economic growth stagnates amid the U.S.-China trade war.

But OPEC stopped short of pledging action beyond March and analysts have questioned the impact of the latest curbs.

Brent futures were down 18 cents at $63.21, but are set to rise 1.5% on the week.

West Texas Intermediate oil futures fell 33 cents to $58.10 a barrel. They are set to rise nearly 6% on the week.

The cuts next year will expand the existing agreement by an extra 500,000 barrels per day (bpd) reduction in the first quarter next year, through tighter compliance and some adjustments. OPEC's current agreement is a supply cut of 1.2 million bpd and the increased amount represents about 1.7% of global oil output.

Source : Reuters