A top Senate Democrat on Monday decried President Trump's firing of an Obama-appointed acting attorney general. Senate Minority Leader Chuck Schumer blasted the move as defying the point of accountability in the executive office.

"The firing of Sally Yates underscores how important it is to have an Attorney General who will stand up to the White House when they are violating the law. Many people have doubts about whether Jeff Sessions can be that person, and the full Senate and the American people should at the very least know exactly how independent he plans to be before voting on him," Schumer said in a statement released Monday evening.

"The Attorney General should be loyal and pledge fidelity to the law, not the White House. The fact that this administration doesn't understand that is chilling."

Trump announced on Monday evening that he had replaced acting U.S. Attorney General Sally Yates, hours after she criticized his executive order on immigration.

The White House announced the unusual move in a scathing statement, calling Yates "weak on borders and very weak on illegal immigration." Yates was appointed deputy attorney general by former President Barack Obama last January.

"The acting Attorney General, Sally Yates, has betrayed the Department of Justice by refusing to enforce a legal order designed to protect the citizens of the United States," the statement read.

"Tonight, President Trump relieved Ms. Yates of her duties and subsequently named Dana Boente, U.S. Attorney for the Eastern District of Virginia, to serve as Acting Attorney General until Senator Jeff Sessions is finally confirmed by the Senate, where he is being wrongly held up by Democrat senators for strictly political reasons," read the White House statement.

Earlier on Monday, Yates had instructed the Justice Department not to defend the executive order, which halts refugee and asylum programs from seven majority-Muslim countries.