Britney Spears and Kevin Federline have reached a new child support agreement, but E! News has learned that the singer is "very unhappy" over the outcome.

The Blast reports that the 36-year-old "Gimme More" songstress has agreed to pay her 40-year-old ex "thousands more a month in child support." This news comes one month after Spears was ordered to pay Federline $110,000 in their ongoing child support battle.

"They are not happy and think the settlement is ludicrous," a source tells E! News regarding Spears' team's reaction to the new agreement. "But they wanted to make an agreement so that they could move on."

As for Brit, the insider says she's "very unhappy" but understands it's "in her best interest" to move on from the legal turmoil. "She was tired of fighting about it and is ready to get on with her life and put this behind her," explains the source.