Christina Aguilera plans to marry Matthew Rutler at Christmas.

The 'Voice' USA mentor, who is expecting her first child with her fiancé, is reportedly scouting for tropical venues for their nuptials, as she wants to tie the knot a few months after their daughter is born.

A source said: ''They love Hawaii, where they got engaged, but Christina is worries about privacy, so they might rent a private island.''

The singer, who also has son, Max, six, from her first marriage to Jordan Bratman, wants a ''laid back'' wedding.

The insider added to Life & Style magazine: ''It will be a nondenominational ceremony. Last time Christina got married, it was officiated by a rabbi. This time, it will be a lot more laid back.''

Matt proposed to Christina in February, and it was previously revealed he spent a year designing the perfect engagement ring.

A source said: ''Matt has been working on the ring for over a year and been working on the proposal for several months.

''Matt spent a year's time mastering all the specific details with the designer to signify their love and their journey together - it's all reflected in the ring.''

Matt - who has been dating Christina since they met on the set of her 2010 movie 'Burlesque', on which he was a production assistant - took inspiration from two of the 'Beautiful' hitmaker's favourite pieces of jewellery and thought carefully about the meaning behind the nine gemstones which accompany the diamond.

The source continued: ''Matt knew what her two favourite rings were and married them together into one, incorporating all the details that she specifically loved. Every jewel and diamond placing has a reason and meaning for being placed there.''