Homeland Security Secretary Kirstjen Nielsen Resigns

A shake-up at the Department of Homeland Security.

President Trump has announced that Homeland Security secretary Kirstjen Nielsen is being replaced.

The news comes as President Trump sets his sights on a tougher approach to immigration.

Nielsen was with the president in California on Friday, as he highlighted two miles of newly renovated fencing along the US-Mexico border.

On Saturday, the president repeated his argument that the immigration system is overloaded.

Sunday, President Trump met with Nielsen at the White House, where senior administration officials say they were planning to speak about immigration and border issues.

After that meeting, President Trump announced her resignation on Twitter.

He named Kevin Mcaleenan, the commissioner for Customs and Border Protection, as acting secretary of the DHS.

Nielsen says she has agreed to stay on as secretary until Wednesday.