Defense Secretary James Mattis said immigrant members of the military who are currently protected by the Deferred Action for Childhood Arrivals program will continue to be protected — even if the program expires without congressional action next month.

Mattis, speaking to CBS News Pentagon correspondent David Martin and other reporters Thursday, said he has spoken with Homeland Security Secretary Kjirsten Nielsen and confirmed that anyone who has enlisted in the military and is waiting to report to boot camp, anyone on active duty or in the active reserves or anyone with an honorable discharge will not be deported. Two exceptions for that would be for anyone who has committed a serious felony or is the subject of a deportation order.

If Congress fails to act before March 5 — the deadline upon which the program is set to expire — "they're protected," Mattis said.

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But relatively few members of the military currently benefit from DACA. In September, the Pentagon said fewer than 900 people currently serving or who have signed contracts to serve are recipients of the program.

"There are less than 900 individuals currently serving in the military, or have signed contracts to serve, who are recipients of Deferred Action for Childhood Arrival (DACA) authorization," Pentagon spokesman Lt. Col. Paul Haverstick said in a statement in September. "These individuals are part of the Military Accessions Vital to the National Interest (MAVNI) Pilot Program. The Department of Defense is coordinating with the Departments of Justice and Homeland Security (DHS) regarding any impact a change in policy may have for DACA recipients. The department defers to our colleagues at DHS on questions related to immigration, naturalization or citizenship."

MAVNI is a special DOD recruitment program that selects legal immigrants who are deemed to have vital skills serve in the military. Qualifying program enrollees include physicians, nurses and experts in a number of languages in the Middle East and Asia, according to the Pentagon.

President Trump announced in September that he would be ending the program. So far, Congress has yet to agree on a solution for the roughly 690,000 people who are currently DACA recipients. Mr. Trump wants to expand the protections to roughly 1.8 million immigrants who came to the U.S. illegally as children.

CBS News' Caroline Horn contributed to this report.