Cara Delevingne wants to marry Michelle Rodriguez and is planning their wedding.

The British model is reportedly ''deadly serious'' about making her relationship with the 'Machete Kills' actress official and she is hoping to tie the knot in a secret wedding at the Niagra Falls, Canada.

A source told the Daily Star newspaper: ''It's typical of Cara to want to do something crazy and impulsive. But she seems deadly serious.

''They've talked about what kind of big day they'd have. Cara says she wants them to wed in their own element with no priest or anyone with a religious background.''

It's thought Cara, 21, is keen to do something out of the ordinary and is eyeing up a helicopter ride for the nuptials.

The source added: ''She thinks flying above Niagara falls would be perfect - like a no man's land.''

The move towards an official declaration of love follows the couple's commitment ceremony during a trip to Thailand earlier this month, and although the proceedings weren't legally binding, they celebrated their blossoming relationship with a religious Baci ceremony known to locals as the kwan.

A source explained: ''It can symbolise anything precious like a bond or an achievement, and shows how much they want to make a commitment to each other.''