In the aftermath of Donald Trump’s election to a second term as president, attention has turned to his highest-profile campaign promise: the mass deportation of millions of undocumented immigrants living in the United States.

With a governor’s approval, the National Guard can detain individuals, but the other military branches can only offer logistical support for immigration enforcement.

Several sanctuary cities say they will not aid President-elect Donald Trump with the mass deportations he has vowed to carry out once he gets to the White House. City leaders say that Trump does not have the authority to force local law enforcement to comply with the deportations.

Oklahoma Gov. Kevin Stitt (R) said he would help President-elect Trump deport illegal immigrants in his state during a Friday appearance on Fox News. Stitt has already placed the Commissioner of Public Safety in charge of these efforts which will start within prison systems,