Donald Trump has fired the acting US attorney general, Sally Yates, after she questioned the legality of his immigration ban and replaced her with Mr Boente.
Sally Yates, who had been appointed under Barack Obama, earlier ordered justice department lawyers not to enforce the president Trump’s executive order.
President Trump’s order temporarily banned nationals from seven Muslim-majority countries from entering the US, and sparked street protests in the US and abroad.
A statement from the White House said Ms Yates had “betrayed” the department.
She had “betrayed the department of justice by refusing to enforce a legal order designed to protect the citizens of the United States”, a statement from the press secretary said.
It also described her as “weak on borders and very weak on illegal immigration”.
Dana Boente, US attorney for the Eastern District of Virginia, replaces her as acting attorney general. He 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.
The Democrats are delaying my cabinet picks for purely political reasons. They have nothing going but to obstruct. Now have an Obama A.G.
— Donald J. Trump (@realDonaldTrump) January 31, 2017
In a letter, Ms Yates had said she was “not convinced” that the president’s order was lawful.
According to her, the department of justice will not present arguments in defence of the Executive Order as long as she is the acting attorney general.