President Donald Trump has fired the acting US attorney general, after she questioned the legality of his immigration ban. Sally Yates, who had been appointed under Barack Obama, earlier ordered justice department lawyers not to enforce the president's executive order.
In a statement, the White House said Ms Yates had betrayed the department. Dana Boente, US attorney for the Eastern District of Virginia, replaces her as acting attorney general.
Mr Trump's order temporarily banned nationals from seven Muslim-majority countries from entering the US, and sparked street protests in the US and abroad.
In a letter, Ms Yates had said she was not convinced that the president's order was lawful. As long as I am the acting attorney general, the department of justice will not present arguments in defence of the Executive Order, she said.
But the White House said she had betrayed the department of justice by refusing to enforce a legal order designed to protect the citizens of the United States.
President Trump relieved Ms Yates of her duties, a statement from the press secretary said.
Her replacement, Mr. Boente, was also appointed by Barack Obama, in 2015. He was confirmed by the US Senate - making him eligible for appointment while Mr. Trump waits for his own nominee to be approved.
Senator Jeff Sessions is awaiting a confirmation hearing for the role later this week.
Meanwhile, hundreds of diplomats and foreign servants have been drafting a dissent cable to formally criticise the president's executive order.
A draft version of the cable said that immigration restrictions will not make the US safer, are un-American and will send the wrong message to the Muslim world. The ban bars citizens from Iraq, Syria, Iran, Libya, Somalia, Sudan and Yemen.
The White House has consistently defended Trump's executive order despite the controversy, with press secretary Sean Spicer saying diplomats should get with the program.
In addition, former President Barack Obama has apparently broken with the convention of former presidents avoiding comment on their successors. Commenting on the protests about the immigration order, President Obama said he was heartened.
Citizens exercising their constitutional right to assemble, organize and have their voices heard by their elected officials is exactly what we expect to see when American values are at stake, he said in a statement, which did not mention president Trump by name.