US secretary of homeland security Kirstjen Nielsen will be leaving her position, President Donald Trump has announced.

In a series of tweets on Sunday, President Trump said: “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!”

Nielsen, 46, had held the position since December 2017. She led a sprawling department responsible for carrying out some of Trump’s most contentious policies, such as his plan to build a wall on the border with Mexico and the separation of migrant children from their families.

Nielsen’s departure comes after Trump renewed his public expressions of frustration about security at the U.S. southern border, including during a visit to California on Friday in which he declared the U.S. “full” and unable to accommodate any more migrants from Latin America.

Tougher

On Friday, Trump withdrew his nominee to run immigration and customs enforcement to appoint someone “different” and “tougher”.

“We’re going in a tougher direction. We want to go in a tougher direction,” Trump said Friday of Ronald Vitiello, the acting director of the immigration agency.

Last week, Trump threatened to close the US border with Mexico to stop a spike in migration. Customs and border protection apprehended 66,450 who crossed the border illegally in February, an increase of more than 18,000 from the month before.

Trump reportedly has previously considered removing Nielsen in frustration about the porous southern border. The president and other White House officials have been frustrated by the slow, tangled process to move new immigration proposals through the government, which often requires sign-off from as many as four different cabinet agencies.

Nielsen has been caught in the cross-hairs of those frustrations. She’s also a protege of former White House chief of staff John Kelly, who departed the White House in January.

(Reuters, Bloomberg)