Zac Efron got down on one knee and extended the proposal of marriage to girlfriend Vanessa Hudgens, according to reports.

The High School Musical co-stars - who have been dating for three years - were on a promotional trip to Japan when Zac decided to pop the question, it is claimed.

"He adores Vanessa, and they gel really well together", a source tells the National Enquirer.

And Zac doesn't have to worry about gaining the seal of approval from Vanessa's family, as her mum Gina is said to be thrilled at the thought of Zac whisking her daughter off into the sunset.

The source adds, "Gina already considers Zac part of the family, so she's happy that he proposed.

"She is old-school and doesn't approve of Vanessa living with Zac without some type of wedding promise."

See Zac and Vanessa from the beginning below