The president’s Day 1 actions included directives that fly in the face of legal limits on involving the military in domestic operations and the constitutional guarantee of birthright citizenship.

Mr. Trump is planning to attempt to deny birthright citizenship to the children of immigrants who are in the U.S. illegally, according to the incoming officials. The U.S. government has long interpreted the U.S. Constitution to mean that those born on American soil are citizens at birth, regardless of their parents' immigration status.

A top US Justice Department official installed by Donald Trump warned prosecutors that they must comply with the president’s hard-line immigration agenda and laid the groundwork for a clash with state and city officials who don’t cooperate with the administration’s crackdown.