WASHINGTON — The Justice Department said Wednesday that it had created an official section in its immigration office to strip citizenship rights from naturalized immigrants, a move that gives more heft to the Trump administration’s broad efforts to remove from the country immigrants who have committed crimes.

The Denaturalization Section “underscores the department’s commitment to bring justice to terrorists, war criminals, sex offenders and other fraudsters who illegally obtained naturalization,” Joseph H. Hunt, the head of the Justice Department’s civil division, said in a statement.

“The Denaturalization Section will further the department’s efforts to pursue those who unlawfully obtained citizenship status and ensure that they are held accountable for their fraudulent conduct,” Mr. Hunt said.

The move promises to further expand a practice that was once used infrequently, but that the Trump administration has increasingly turned to as part of its immigration crackdown. It has raised alarms among some department lawyers who fear denaturalization lawsuits could be used against immigrants who have not committed serious crimes.