US pop star Madonna admits she wasn\'t happy to see photos published showing her 15-year-old daughter, Lourdes Leon, smoking a cigarette. \"I wasn\'t very happy,\" the single mother of four told Harry Smith in an interview for TV\'s \"Rock Center with Brian Williams.\" \"Honestly, I don\'t think I\'m as tough as I should be [on my kids]. I think I need to be maybe tougher. It\'s hard -- every day is a negotiation,\" she said. \"But cigarette smoking I\'m not very fond of for anyone. I don\'t approve of anyone smoking cigarettes -- most of all my daughter.\" Smith then noted Madonna smokes in her new \"Girl Gone Wild\" music video. \"I don\'t smoke,\" she said. \"That\'s just an accessory, Harry. There\'s a difference. [Lourdes] smoked that cigarette before I did that video.\"