NEW YORK, Dec. 2 (Xinhua) -- Oil prices dropped on Friday ahead of a key meeting by the Organization of the Petroleum Exporting Countries and its allies, collectively known as OPEC+.

The West Texas Intermediate (WTI) for January delivery lost 1.24 U.S. dollars, or 1.5 percent, to settle at 79.98 dollars a barrel on the New York Mercantile Exchange. Brent crude for February delivery decreased 1.31 dollars, or 1.5 percent, to close at 85.57 dollars a barrel on the London ICE Futures Exchange.

OPEC+ will meet on Sunday. In October, the oil alliance agreed to reduce its output target by 2 million barrels per day from November to shore up prices.

Experts said the group is likely to leave its output unchanged at the upcoming meeting.

"In view of the many uncertainties on the market, it is unlikely to implement any further measures this Sunday," Barbara Lambrecht, energy analyst at Commerzbank Research, said in a note on Friday.

"After all, the EU's oil embargo on (seaborne) crude oil from Russia will come into force on Monday, and it is still unclear what effect the price cap on Russian oil will have," she said.

The European Union (EU) member states on Friday agreed on a 60 U.S. dollar per barrel cap on the price of Russian seaborne crude.

For the week, the WTI advanced nearly 4.9 percent, while Brent rose 2.2 percent, based on the front-month contracts.