WASHINGTON (AP) — The Trump administration is creating a registry for all people who are in the United States illegally, and those who don’t self-report could face fines or prosecution, immigration officials announced Tuesday.

Everyone who is in the U.S. illegally must register, give fingerprints and provide an address, the Department of Homeland Security said in a statement. It cited a section of the Immigration and Nationality Act — the complex immigration law — as justification for the registration process, which would apply to anyone 14 and older.

The announcement comes as the administration seeks to make good on campaign promises to carry out mass deportations of people in the country illegally and seal the border to future asylum-seekers.

“An alien’s failure to register is a crime that could result in a fine, imprisonment, or both,” the statement said. “For decades, this law has been ignored — not anymore.”

On its website, the U.S. Citizenship and Immigration Service said it would soon create a form and process for registration.

In one of his 10 inauguration day executive orders related to immigration, President Donald Trump initially outlined plans for creating a registry and required that Homeland Security “immediately announce and publicize information about the legal obligation of all previously unregistered aliens in the United States to comply.”

It was not immediately clear how many people living in the country illegally would voluntarily come forward and give the federal government information about who they are and where they’re living. But failure to register would be considered a crime, and the administration has said its initial priority target for deportation is people who’ve committed crimes in the U.S.

The National Immigration Law Center, an immigration advocacy group, said in a posting on its website before the Tuesday night announcement that “the Alien Registration Act of 1940 is the only time the U.S. government carried out a comprehensive campaign to require all noncitizens to register.”

The organization said under that process, people had to go to their local post office to register, and the goal was to identify “potential national security threats broadly characterized as communist or subversive.”

The group warned that the registry was meant to help find potential targets for deportation.

“Any attempt by the Trump administration to create a registration process for noncitizens previously unable to register would be used to identify and target people for detention and deportation,” the organization said.