Michelle Obama appeared on "The Tonight Show Starring Jimmy Fallon" Tuesday night.

During the interview, Obama joked that her husband was motivated to seek a second term because he wanted their daughters to spend their teen years under the guard of the Secret Service.

"He was like, 'We've got to win, because I don't want those girls walking around,'" Obama recalled.

Forget gun control and healthcare reform — former President Barack Obama had a personal reason for wanting to win a second term so badly.

During an appearance on the "Tonight Show" Tuesday night, former First Lady Michelle Obama said her husband was motivated to win reelection because he wanted to keep their daughters under the guard of the Secret Service.

"I've always said, as quiet as it's kept, the second term of the presidency was really fueled by Barack's desire to keep them with their agents into their teen years," she said.

"He was like, 'We've got to win, because I don't want those girls walking around.' He wanted men with guns with them. He worked extra hard on those votes. He's like, 'Come on voters!'" Obama recalled.

The couple's daughters, Malia and Sasha, were 14 and 11 years old, respectively, when their father was inaugurated for his second term in the White House.

Read more: Michelle Obama and Jimmy Fallon surprised people in the 30 Rock elevators, and their reactions were priceless

The family decided to stay in Washington, DC, after Obama's second term was up so that Sasha, now 17, could finish high school. Eldest daughter Malia, now 20, is in her second year at Harvard.

Barack Obama and his daughter Malia. REUTERS/Kevin Lamarque

During the interview, Obama said she enjoys the relationship she has with her daughters now that they are older.

"I love the baby stage. I'm like you — I love every age, but now they're really interesting. We're friends," she said. "There are boyfriends we can talk about. You know, they drive, so they can earn money, so they ask for less. I love it."

Obama appeared on the show to promote her new memoir, "Becoming," which is at the top of the New York Times bestseller list for hardcover nonfiction.