The Department of Justice's top career official for public corruption resigned Monday after the Trump administration reassigned him to handle immigration matters, the New York Times reported on Monday, citing the resignation letter.

Corey Amundson had served in the DOJ for more than two decades.

“I spent my entire professional life committed to the apolitical enforcement of federal criminal law and to ensuring that those around me understood and embraced that central tenet of our work,” he wrote to acting Attorney General James McHenry.

His resignation comes as the Trump team works to overhaul the DOJ amid allegations of political weaponization. Trump himself has furiously criticized the department over its handling of prosecutions against him.

Last week, the Trump administration reassigned him to a group dedicated to dealing with sanctuary cities.