Department of Homeland Security Secretary Kirstjen Nielsen is stepping down. The news was announced by President Trump on Twitter Sunday evening. CNN is reporting Trump ousted Nielsen following months of reported tensions between the two. Nielsen oversaw Trump’s “zero tolerance” family separation policy and came under fire by Democrats for lying to Congress about the policy, as well as for withholding information on children who died in U.S. custody. In June of last year, Nielsen tweeted, “We do not have a policy of separating families at the border. Period.” In a statement, House Speaker Nancy Pelosi said, “It is deeply alarming that the Trump Administration official who put children in cages is reportedly resigning because she is not extreme enough for the White House’s liking.” Kevin McAleenan, the current U.S. Customs and Border Protection commissioner, will become the acting head of Homeland Security. On Friday, Trump withdrew nominee Ronald Vitiello to head Immigration and Customs Enforcement, indicating he wasn’t “tough” enough for the role.

Meanwhile, immigration and civil rights groups are urging Fortune 500 companies not to hire former Trump administration officials who were involved in separating migrant families. A letter signed by 41 groups, including the Southern Poverty Law Center, reads, “They should not be allowed to seek refuge in your boardrooms or corner offices. Allowing them to step off of the revolving door and into your welcoming arms should be a non starter.”