() Immigrants who are in the United States illegally and who do not comply with the Trump administration’s new registration requirement could face fines or prosecution.

“The Trump administration will enforce all our immigration laws we will not pick and choose which laws we will enforce,” a Department of Homeland Security spokesperson said. “We must know who is in our country for the safety and security of our homeland and all Americans.”

The department said in a statement that all undocumented individuals must register, give fingerprints and provide an address. The move is based on the Immigration and Nationality Act, which applies to anyone age 14 or older.

“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.”

Once registered and fingerprinted, people will receive proof of registration, which must be carried at all times for those over 18.

U.S. Citizenship and Immigration Services will soon provide a registration form on its website.

Migrants who entered without proper documentation or overstayed their visas must register within 30 days of remaining in the country. Additionally, anyone turning 14 while in the U.S. must register within 30 days of their birthday.

It’s unclear how many undocumented individuals will voluntarily come forward, but failure to register will be considered a criminal offense. The administration has prioritized deporting individuals with criminal records in the U.S. as part of its broader immigration efforts, which include mass deportations and border enforcement measures.

This announcement follows President Donald Trump’s executive orders aimed at fulfilling campaign promises regarding immigration, including creating a registry and urging the DHS to “immediately announce and publicize information about the legal obligation of all previously unregistered aliens in the United States to comply.”

The Associated Press contributed to this report.