Breaking update: President Trump announced Nielsen is “leaving her position”. Trump did not say she was resigning, as initial reports stated, instead saying she was “leaving her position”, implying he may have fired Nielsen.
“Secretary of Homeland Security Kirstjen Nielsen will be leaving her position, and I would like to thank her for her service……..I am pleased to announce that Kevin McAleenan, the current U.S. Customs and Border Protection Commissioner, will become Acting Secretary for @DHSgov. I have confidence that Kevin will do a great job!”
Secretary of Homeland Security Kirstjen Nielsen will be leaving her position, and I would like to thank her for her service….
— Donald J. Trump (@realDonaldTrump) April 7, 2019
….I am pleased to announce that Kevin McAleenan, the current U.S. Customs and Border Protection Commissioner, will become Acting Secretary for @DHSgov. I have confidence that Kevin will do a great job!
— Donald J. Trump (@realDonaldTrump) April 7, 2019
Update: Copy of Nielsen resignation later (with year typo).
Nielsen was not planning to resign when she walked into her meeting with Trump today, but she was prepared for the possibility. Here is her resignation letter, per a source close to Nielsen: pic.twitter.com/ElyTiwbYuR
— Jeremy Diamond (@JDiamond1) April 7, 2019
Original TGP report: CBS News is reporting Secretary of Homeland Security Kirstjen Nielsen is expected to resign Sunday evening during a 5 p.m. meeting at the White House with President Trump. CBS’s Paula Reid broke the story on Twitter just after 5 p.m. EDT.
JUST IN: Two US officials tell @CBSNews DHS Secretary Kirstjen Nielsen meeting with President Trump at 5pm, expected to resign.
— Paula Reid (@PaulaReidCNN) April 7, 2019

Homeland Security Sec. Kirstjen Nielsen, screen image.
Excerpt from CBS report:
“…Nielsen’s expected departure is a part of a massive DHS overhaul engineered and directed by top Trump adviser Stephen Miller, according to a senior U.S. official. It’s unclear whether Nielsen is deciding to resign voluntarily, or whether she has been pressured to resign. Nielsen has served as DHS secretary since December 2017, and questions about how much longer she might last have swirled for months, as the president continues to articulate his frustrations about illegal immigration…”
End excerpt. Please read complete CBS News report at this link.
This post will be updated.
Update: Other White House reporters are scrambling in response to the CBS report.
The NY Times’ Maggie Habermann says some White House staffers taking wait and see attitude for the outcome of the meeting.
Nielsen meeting in WH residence with POTUS. Multiple WH aides say they expect she leave, but say they've seen versions of this script with her and POTUS before and are waiting to see outcome of meeting before saying anything definitive.
— Maggie Haberman (@maggieNYT) April 7, 2019
CNN’s Jake Tapper was told Nielsen had no intention to resign going into the meeting.
At this hour, the status of DHS Secy Nielsen is unclear. A senior admin. official tells me that she had a 5 PM meeting at the WH with POTUS where she was planning to discuss with him the immigration and border issues and a path forward — she had no intention of resigning…
— Jake Tapper (@jaketapper) April 7, 2019
Fox News’ John Roberts reports Nielsen job is on the line in the meeting.
.@FoxNews is told @DHSgov Secretary @SecNielsen is meeting with @realDonaldTrump right now about her future.
— John Roberts (@johnrobertsFox) April 7, 2019