(Conrad Schmidt/AFP/Getty Images)

First lady Michelle Obama says the shooting of 17-year-old Trayvon Martin in a Florida neighborhood in February is a "tremendous loss" and that all Americans "have to rally around that piece of it."

Obama made her first public comments on the case in an interview with NPR that aired today.

"All I can say is that, you know, my heart goes out to the parents, because we all as parents understand the tragedy of that kind of loss, and I think that's really the thing that most people connect to," she said.

"And it's important for us not to lose sight of the fact that this is a family that's grieving and there's been a tremendous loss," she said. "And we all have to rally around that piece of it."

Martin, 17, was unarmed when volunteer neighborhood watchman George Zimmerman shot him as he was returning to his father's home after buying Skittles and tea at a gas station on Feb. 26.

Zimmerman, who claimed self-defense, was questioned but not immediately arrested or charged. He has since been charged with second degree murder.

The first lady said the national dialogue sparked by the incident "can't come in spits and starts" but must continue in order to "understand our communities and the challenges that we face, which are different and unique depending upon where you live."

"It's all about, you know, continuing to get to know ourselves in a very diverse and complicated country that is America. It is a wonderful place to live. But because it is so diverse, our challenges are complex," she said. "So there isn't, you know, a one-shot solution to this. It is complicated. It takes time. It takes openness. It takes compassion. It takes patience. And it takes a lot of work."