Saudi Arabia said it plans to cut oil exports to all the regions it ships to next month as the kingdom and fellow OPEC nations press on with their effort to clear a global glut.

Shipments will fall by 120,000 barrels a day in December from November, a spokesman for the Energy Ministry said, without specifying what those levels would be. Bloomberg calculations from vessel-tracking data estimated flows in October at 6.989 million a day. It’s unusual for the ministry to comment publicly on exports.

Shipments to the U.S. will decrease month-on-month by 10 percent in December, the Saudi Energy Ministry said. The U.S. imported 816,000 barrels a day from Saudi Arabia in the week to Nov. 3, according to the U.S. government’s Energy Information Administration. Imports averaged 506,000 barrels a day in October, the data show.

The Organization of Petroleum Exporting Countries and Russia have led a global alliance of oil producers this year in output cuts aimed at ending a three-year glut that has depressed prices and battered their economies. It’s finally showing signs of success, with about half of the surplus in oil inventories cleared and prices at their highest since 2015.

The producers will meet on Nov. 30 in Vienna, where they may decide whether to prolong the cutbacks beyond their scheduled expiry in March. Speculation has grown that they’ll extend the measures to the end of 2018 after Russian President Vladimir Putin signaled last month that he’s open to such a move.

A decline in the kingdom’s exports at this time of year would be in keeping with normal seasonal trends. Saudi Arabia’s shipments have fallen between November and December every year since 2009, by an average 243,000 barrels a day, according to data the country submits to the Joint Organizations Oil Data Initiative.