WASHINGTON--U.S. Homeland Security Secretary Kirstjen Nielsen, who became best known for defending President Donald Trump's policy of separating migrant children from their parents, said on Sunday she was leaving her position effective immediately.
Nielsen's departure was first reported by CBS News. A senior administration official said Trump asked for Nielsen's resignation and she gave it.
Trump said on Twitter: "Secretary of Homeland Security Kirstjen Nielsen will be leaving her position, and I would like to thank her for her service."
In another tweet, Trump said Kevin McAleenan, the current U.S. Customs and Border Protection commissioner, would become acting DHS secretary.
Nielsen, 46, had been DHS secretary since December 2017. Her time overseeing the sprawling department included conflict with Trump and overseeing a policy of separating children from their immigrant parents at the border with Mexico.
Trump has made a clampdown on illegal immigration a centerpiece of his two-year-old presidency, as he has sought to cut back on the number of newcomers, especially Mexicans and Central Americans, entering the United States without proper documentation.
Nielsen's departure was announced two days after the Republican president abruptly said on Friday he was dumping his own nominee to be the top officials at U.S. Immigration and Customs Enforcement (ICE), Ronald Vitiello, saying he wanted someone "tougher." ICE is under the jurisdiction of DHS.
Repeatedly subjected to tough questioning by Democrats at congressional hearings, Nielsen became a lightning rod for criticism of Trump's policies. She was confronted by protesters last year at a Mexican restaurant in Washington.
As leader of DHS, Nielsen was responsible for carrying out some of Trump efforts such as his battle to build a wall on the border with Mexico, stepped-up deportations and treatment of migrant children, as images of children being held in cages were spread around the world. Trump insists that the arrival of immigrants across the southern U.S. border constitutes a national emergency so important that he sidestepped Congress' refusal to provide him with several billion dollars he requested to build the border wall.
