Obama was on hand to greet incoming Interior Secretary Sally Jewell, formerly the CEO of the sporting good retailer REI, who started on the job last week.
The first lady drew a connection between the Interior Department and her well-known push to curb childhood obesity with her "Let's Move" campaign.
"What you do here at Interior is absolutely critical for our children's health and well-being," Obama said. "It's important to expose our kids to the natural resources available right here in this country. That's what I think about when I think about what you all do."
She also acknowledged unpopular worker furloughs instituted at the department as part of across-the-board spending cuts known as the sequester.
"I know you all are juggling more responsibilities with fewer resources," she said. "I want you to know how much [President Barack Obama] and I appreciate what you do. Hang in there and know that what you do is extremely important. Our country needs you."