LOS ANGELES — 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, two, and Jayden James, one. 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."

"He has no intention of taking these children out of their mother's life," Kaplan said. "We have no doubt that she loves the children immensely and they are bonded with her."

Federline's household provides more consistent routines for the boys, Kaplan said.

"If you have one home with structure and one without structure, the children will be confused," he said. "Kids don't like discipline imposed on them and they would choose the one without structure. But there's a need for consistency."

He said Federline has been employing a well-qualified nanny who has been involved in the boys' care since he took custody.

Seacrest apparently woke Spears up when he called her for the interview, and at times she didn't seem to understand his questions. When Seacrest asked Spears whether the intense coverage of her recent troubles has been "overwhelming," she said, "Wait, what?"

However, she then said: "People talk and they say what they want at the end of the day, you know in the tabloids and in the magazines," she said. "But you just try to keep on doing what you do, like, you know, and as long as you know what's up and you know what's true, that's all that really matters, you know?"

Spears' "Blackout," her first studio album in four years, was released Tuesday. Besides a video for "Gimme More" and a widely panned performance at the MTV Video Music Awards, she hasn't promoted the record.

Spears said she didn't do anything special to celebrate the release — "we watched movies ... had fried chicken."

She said her favourite "Blackout" song is "Heaven on Earth": "It's a cool track. It's like, I love the producers who did that and it's kind of different from all the other songs."

As for rumors that she was dating Dallas Cowboys quarterback Tony Romo, Spears said: "Who?"

The interview ended abruptly when Sims took the phone, saying Spears had left to take a shower.