Robbie Williams says his daughter Coco is the ''most chilled baby'' he has ever known.

The 44-year-old singer has opened up for the first time about his and wife Ayda Field's surprise new addition after they welcomed Colette 'Coco' Williams into the world last week via surrogacy, and the 'Angels' hitmaker is ''relaxed'' about becoming a dad for a third time.

Robbie - who also has kids Teddy, five, and Charlton, three, with Ayda - said: ''Coco is the most chilled baby I've ever known.

''It's funny. The first baby you have, 'Shh, it's sleeping,' then you hear someone coming in that closes the door and you run downstairs and you go, 'Shh! The baby!'

''Then the third one, the television's on, the kids are playing, the dogs are barking, the baby stays asleep and the world doesn't end.

''I wonder if the baby is so relaxed because we are relaxed.''

Robbie is pleased Teddy and Charlton are ''not jealous'' of their new sister.

He added to The Sun newspaper: ''The kids are getting on really well with her, there's no jealousy.

''In fact there's just lots of love and cuddles and Teddy wants to feed her all the time. So that's what's going on.''

The couple announced last week they had become parents for a third time after a ''long and difficult'' struggle to have another baby.

Taking to Instagram, Ayda wrote: ''I spy with my little eye an extra little hand ... So we have been keeping a very special secret! We are delighted to share with you that we have had a baby girl....welcome to the world Colette (Coco) Josephine Williams!!

''It has been a very long and difficult path to get here, which is why we have kept it on the down low. Family comes in all forms, and this little lady, who is biologically ours, was carried by an incredible surrogate mother, to whom we will be eternally grateful. We are over the moon to have this beautiful baby girl in our lives and so blessed that we live in a world which makes this possible. As with Teddy and Charlie, we ask that you respect Coco's privacy and allow us to grow into our new team of 5! #TeamWilliams (sic)''