President Donald Trump and White House allies pushing for a harder line on immigration sped their campaign Monday to clean house at the Department of Homeland Security with a mission far wider than just the departure of Secretary Kirstjen Nielsen.

The head of U.S. Citizenship and Immigration Services, L. Francis Cissna, and Homeland Security General Counsel John M. Mitnick are expected to be leave their positions, according to people familiar with the matter.

Nielsen submitted her resignation Sunday after meeting with Trump at the White House, and three days earlier the administration withdrew the nomination of Ron Vitiello to lead Immigrations and Customs Enforcement. Other longtime civil servants in agency posts are also expected to leave, said officials who spoke on condition of anonymity because they were not authorized to speak publicly, the Associated Press reports.

Trump announced Sunday that U.S. Customs and Border Protection Commissioner Kevin McAleenan would take over for Nielsen at Homeland Security on an acting basis. Trump spokesman Hogan Gidley expressed hope that McAleenan's experience would lead to “massive changes” at the border.

Additionally, the director of the Secret Service Randolph Alles is leaving his job, but that departure is said to be unrelated to the immigration upheaval.