Current Department of Homeland Security Secretary Kirstjen Nielsen is resigning her position after a previously unremarked but scheduled meeting at the White House on Sunday.

Nielsen has faced criticism over the last year, and has been a subject of recent critical segments from Fox's Lou Dobbs regarding her actions or, as some see it, perceived inaction on the border crisis. In November it was reported that Nielsen was going to be replaced, but she continued on in her role.

Not so this time, as the President confirmed moments ago on Twitter.

"Secretary of Homeland Security Kirstjen Nielsen will be leaving her position, and I would like to thank her for her service," said the President. He followed up that Tweet with a second announcing his pick to replace her.

".I am pleased to announce that Kevin McAleenan, the current U.S. Customs and Border Protection Commissioner, will become Acting Secretary," he said. "I have confidence that Kevin will do a great job!"

Just a few days ago, President Trump withdrew his nomination of Ronald Vitiello to head up ICE, saying that he wants "go in a tougher direction." The topic of today's meeting with Nielsen was, according to reports, a path forward on those issues. CNN's Jake Tapper notes that rumors are these are only two of several changes in direction that will be coming down, focusing the President's agenda on a more definitive immigration and border policy.

Recently, the President has spoken several times about the idea of shutting down the southern border entirely.

In particular, Trump-supporting immigration hard-liners have recently been especially critical of Nielsen's handling of the emergency declaration. Dobbs lamented last week that the Secretary "waited six weeks from the time the President declared a national emergency to seek emergency authorities."

CBS News was the first to report that Nielsen would resign, and attributed the decision to adviser Stephen Miller and an "overhaul" of all things immigration on his part.

UPDATE: Outgoing Secretary Nielsen makes statement via Twitter.

UPDATE II: Kirstjen Nielsen has agreed to stay on as Secretary of DHS through the 10th (this Wednesday) to facilitate the transition.