By Jeremy Herb - 02/27/13 08:02 PM EST
Hagel was sworn in as Defense secretary Wednesday morning, less than 24 hours after he was confirmed by the Senate.
The Pentagon's Director of Administration and Management Michael Rhodes administered the oath for Hagel in a private ceremony.
Hagel, the first Vietnam veteran to run the Pentagon, also acknowledged in his remarks the budget issues and other challenges that lie ahead in his tenure.
Read more on The Hill's DEFCON blog.