Beyonce Knowles wants more kids.

The 'Halo' singer already has 13-month-old daughter Blue Ivy with husband Jay-Z and is considering adding to their family when she finishes her 'Mrs Carter Show' world tour, which kicks off in April.

Speaking in her documentary 'Life Is But A Dream', Beyonce said: ''I definitely want another child. It was important for me to do what I love and I love to perform and I love to make music.

''I wanted to have my daughter and see if I was still as passionate. Maybe after this next tour I'll maybe have another baby.''

Beyonce recently claimed friendship is the key to her marriage with Jay-Z, 43.

The 31-year-old signer said:''We were friends first for a year and a half before we went on any dates. We were on the phone for a year and a half, and that foundation is so important for a relationship. Just to have someone who you just like is so important, and someone [who] is honest.

''I would not be the woman I am if I did not go home to that man. It just gives me such a foundation. [He's helped me] on so many levels.''