Jack Osbourne is set to become a father any day now.

The 26-year-old 'Adrenaline Junkie' star confirms fiancée Lisa Stelly - who he proposed to last September after a four-month romance - is due to give birth to their first child imminently.

Taking to twitter on Tuesday night (19.04.12), he said: ''Well @lisamarstelly is supposed to give birth to our baby tomorrow. Fingers crossed.''

The former wild child - who was born in England but moved to Beverly Hills in Los Angeles with mum Sharon, dad Ozzy and sisters Kelly and Aimee when he was just 11 - has also just completed the US naturalisation process, and become an American citizen.

Announcing the news on twitter, he joked: ''Woah. I just became a US citizen. Don't worry England I'm still British.''

He also shared a humorous message from his Black Sabbath rocker father, congratulating him on his new-found immigration status.

He said: ''This is what @OfficialOzzy texted me- 'So I guess u have become an American oh well just as long as you r happy I still love you dearly' (sic).''