Britney Spears defended her parenting and decried her critics, lamenting "how cruel our world can be," in a brief interview on Ryan Seacrest's radio show Wednesday.

Spears, always photographed but rarely interviewed these days, also spoke about her new album "Blackout" during the seven-minute talk, during which she giggled frequently as her assistant, Alli Sims, and friend, Sam Lufti, laughed and shouted in the background.

When the "American Idol" host, who has a morning radio show on KIIS-FM in Los Angeles, asked Spears whether she was doing all she could for her children, Spears replied, "Oh, God, yeah."

"People say what they want and do what they do and it's sad how people, how cruel our world can be," she said. "At the end of the day ... you've just got to know in your heart that you're doing the best you can and that's basically it."

Spears' ex-husband, Kevin Federline, has primary custody of her two sons, Sean Preston, 2, and Jayden James, 1. A judge on Tuesday granted Spears three monitored visits a week. She must also take parenting classes and submit to random weekly drug and alcohol tests.

Spears was unclear when Seacrest asked how often she would see the boys.

"That's, like, all in the court," she said. "Stuff like that, my lawyers know all that stuff."

Meanwhile, Federline's attorney, Mark Vincent Kaplan, told The Associated Press that the custody battle is "a painful thing for him."