The U.S. Justice Department will ask a federal judge to modify a court settlement to allow authorities to detain illegal immigrant families together for more than 20 days, a department official said on Wednesday.

"Right now we have the lawful authority to detain a family unit together for up to 20 days. What we are seeking with Judge Gee is a modification of that so we can detain beyond 20 days the entire family unit together," Gene Hamilton, counselor to Attorney General Jeff Sessions, said in a media briefing. He was referring to Judge Dolly Gee of the U.S. District Court for the Central District of California.