Neymar has admitted he 'made a mistake' in a bizarre public apology to his pregnant girlfriend Bruna Biancardi.

In a lengthy Instagram post, the Paris Saint-Germain star vowed he'll 'try' to make their relationship work, and that he's 'done wrong.'

It comes after the couple announced in April that they are expecting their first child together, with influencer Bruna posting sweet snaps of her growing bump.

Neymar wrote: 'Bru. I do this for both of you and your family. Justify the unjustifiable. No need to. But I need you in OUR lives

'I saw how much you were exposed, how much you suffered with all of this and how much you want to be by my side. And I stand beside you.

'I did wrong with you all. I risk saying I'm wrong every day, on and off the pitch. Only I solve my mistakes in personal life at home, in my intimacy with my family and friends...

'All of this hit one of the most special people in my life. The woman I dreamed of following beside me, mother of my child. 

'Has it touched his family, which is my family today. She touched her intimacy in such a special moment that is maternity.

'Bru, I already apologised for my mistakes, for unnecessary exposure, but I feel obligated to come publicly reaffirm that. If a private matter has become public, the apology has to be public.

'Can't imagine without you. I don't know if we'll work out, but TODAY you're sure I want to try.

'Our purpose will prevail, our love for our baby will win, our love for each other will make us stronger. 

'ALWAYS US. I love you .'

Neymar's post comes just days after reports that the couple agreed upon a list of conditions that allow the PSG star to be unfaithful.