US Homeland Security Secretary resigns

WASHINGTON- The Associated Press

Homeland Security Secretary Kirstjen Nielsen resigned on April 7 amid President Donald Trump's growing frustration and bitterness over the number of Central American families crossing the southern border.

Trump announced in a tweet that U.S. Customs and Border Protection Commissioner Kevin McAleenan would be taking over as acting head of the department. McAleenan is a longtime border official who is well-respected by members of Congress and within the administration. The decision to name a top immigration officer to the post reflects Trump's priority for the sprawling department founded to combat terrorism following the Sept. 11 attacks.

"I have determined that it is the right time for me to step aside," Nielsen wrote in her resignation letter.

Though Trump aides were eyeing a staff shake-up at Homeland Security and had already withdrawn the nomination for another key immigration post, the development Sunday was unexpected.

Nielsen traveled to the U.S.-Mexico border on April 5 with Trump to participate in a roundtable with border officers and local law enforcement. There she echoed Trump's comments on the situation at the border, though she ducked out of the room without explanation for some time while Trump spoke. As they toured a section of newly rebuilt barriers, Nielsen was at Trump's side, introducing him to local officials.

Nielsen had grown increasingly frustrated by what she saw as a lack of support from other departments and increased meddling by Trump aides on difficult immigration issues, according to three people familiar with details of her resignation.