SANTA FE, N.M. (AP) — The U.S. government said Wednesday it is appealing a court ruling that would otherwise lift asylum restrictions that have become the cornerstone of border enforcement in recent years.

The enforcement rule first took effect in March 2020, denying migrants’ rights to seek asylum under U.S. and international law on grounds of preventing the spread of COVID-19.

The Homeland Security Department said it would file an appeal with the U.S. Court of Appeals for the District of Columbia, challenging a November ruling by U.S. District Judge Emmet Sullivan that ordered President Joe Biden’s administration to lift the asylum restrictions.

The restrictions were put in place under former President Donald Trump at the outset of the COVID-19 pandemic. The practice was authorized under Title 42 of a broader 1944 law covering public health, and has been used to expel migrants more than 2.4 million times.