US President Donald Trump replaces acting US immigration and customs chief Daniel Ragsdale by Thomas Homan

US President Donald Trump has replaced the acting head of US Immigration and Customs Enforcement (ICE), shortly after the top federal government lawyer was fired for refusing to defend his Muslim ban.

Daniel Ragsdale was relieved of his duties on Monday night by Trump and replaced by Thomas Homan, who has been ICE’s executive associate director of enforcement and removal operations since 2013.

“I am confident that he [Homan] will continue to serve as a strong, effective leader for the men and women of ICE,” Homeland Security Secretary John Kelly said in a statement.

Trump did not give any reason to replace Ragsdale, who was appointed by former President Barack Obama.

Earlier in the day, Trump fired Acting Attorney General Sally Yates after she ordered US Justice Department attorneys not to defend the president’s ban on Muslims from several countries entering the United States. She was also was appointed by Obama.

The White House on Monday accused Yates of betraying the department by refusing to enforce a legal order that was “designed to protect the citizens of the United States.”

Sally Yates, the former Acting Attorney General of the United States

Trump signed an executive order on Friday that imposes a 90-day entry ban for citizens of Iran, Iraq, Syria, Yemen, Sudan, Libya and Somalia, blocks refugees from Syria indefinitely, and suspends all refugee admissions for 120 days.

Trump's sweeping ban sparked protests and chaos at airports on the weekend as customs officials struggled to put the order into practice, and several lawsuits were filed against the ban.

Taking an extraordinarily rare step, Yates defied the White House, saying that the Justice Department would not defend the order against court challenges.