U.S. sanctions against Iran have hit the regime’s oil exports hard as the number of barrels last month fell from around 1.1. million barrels per day—a decrease from around 1.5 million daily in October—reported The Financial Times.

Although exports slightly increased from 1 million barrels each day in November to 1.1. million in December, the reimposition of oil sanctions on Iran in November that were lifted under the 2015 Iran nuclear deal precipitated a fourth-quarter sell-off.

Nonetheless, oil prices worldwide have remained low due to temporary waivers the Trump administration gave to several countries. These wavers expire in March, and according to U.S. special representative for Iran Brian Hook, they are not expected to be extended.