Los Angeles, April 19 - Madonna considers herself a tough mother, but she believes she needs to be tougher.

The singer raises daughter Lourdes, 15, son Rocco, 11, adopted son David, six, and daughter Mercy, six.

"I think I am a tough parent, but honestly I don't think I'm as tough as I should be. I think I need to be tougher. It's hard though. Everyday is a negotiation," contactmusic. com quoted her as saying.

Her eldest daughter Lourdes was seen smoking in New York in March, and Madonna was not very happy with it.

"Cigarette smoking I'm not very fond of, for anyone, I don't approve of anyone smoking cigarettes, most of all my daughter," she said.

Madonna's latest album "MDNA" is out in the market, and she is currently preparing for a world tour over the summer. (IANS)