Jay-Z ''melts'' when his daughter calls him ''Papa''.

The '99 Problems' rapper and his wife Beyonce Knowles are proud parents to 16-month-old Blue Ivy and Jay-Z's mother, Gloria Carter, revealed her son is besotted with the tot.

She told Us Weekly: ''It warms my heart to see how he interacts with his daughter. And when she says, 'Papa,' he just melts. He's a great dad.

''The amazing thing about being a grandmother is that you go get the kids, but when you're tired, you can take them home!''

When asked if her son and his wife are planning more kids in the future, Mrs Carter responded: ''''I think so!''

Beyonce recently admitted she would love to give her 16-month-old daughter a sibling, because she enjoyed such a close relationship with her younger sister Solange Knowles, 26, when they were growing up.

She said: ''I would like more children. I think my daughter needs some company. I definitely love being a big sister.''

When pressed on when she may have another child, she added: ''At some point, when it's supposed to happen.''