The move is intended to ease a massive backlog at U.S. Citizenship and Immigration Services, but not every applicant is eligible.
The Obama administration official says its importance is "impossible to overstate."
Homeland Security is facing a slew of recruiting challenges, including a high rate of polygraph failure, pay parity and a lack of morale, according to employee representatives.
As companies come forward to build border walls, local lawmakers call for divestments in protest
The fee for a naturalization application has increased by $45.