Britney Spears is "very unhappy" about the new child support agreement with her ex-husband Kevin Federline.

Axar.az reports that the 'Piece of Me' hitmaker is reportedly frustrated by the agreement drawn up between herself and her former spouse but knew something had to be worked out so they can "put this behind" them.

A source said: "They are not happy and think the settlement is ludicrous. But they wanted to make an agreement so that they could move on. She was tired of fighting about it and is ready to get on with her life and put this behind her."

Whilst Kevin's attorney Mark Vincent Kaplan added: "I am happy that they came around to resolving this matter. I am sure that they decided the money would be better extended on child support than on attorney's fees, which would've achieved the same result for Kevin but only after months and hundreds of thousands of dollars on litigation. They made a wise decision."

The couple - who split in 2007 - share Jayden James, 11, and Sean Preston, 12 and all "pending matters" surrounding their child support battle have been resolved.