WASHINGTON, April 7 (Xinhua) -- U.S. President Donald Trump Sunday tweeted that Secretary of Homeland Security Kirstjen Nielsen "will be leaving her position".

Current U.S. Customs and Border Protection Commissioner Kevin McAleenan will become acting secretary for the department, Trump said in another tweet.

The announcement came after U.S. news outlets reported Nielsen was set to hand in her resignation letter Sunday evening at a meeting with Trump.

Nielsen supported the Trump administration's tough stance on illegal immigrants, and oversaw controversial policies where immigrant children were separated from their parents for extended periods during detention and trials.

"Nielsen's tenure since she was confirmed in Dec. 2017 has at times been rocky," said CBS News.

McAleenan has been serving as the commissioner of U.S. Customs and Border Protection since Jan. 20, 2017.