WASHINGTON, D.C. ? Virtually all air travelers entering the United States beginning Jan. 23 will need to show passports – even U.S. citizens, the Homeland Security Department announced Wednesday.

Until now, U.S. citizens, travelers from Canada and Bermuda, and some travelers from Mexico who have special border-crossing cards for frequent visitors were allowed to show other proofs of identification, such as drivers’ licenses or birth certificates.

Homeland Security Secretary Michael Chertoff said the change was a crucial next step to helping ensure the nation’s security.

The department had been expected to institute the passport requirement for air travelers around the beginning of the year. Setting the date on Jan. 23 pushes the start past the holiday season.