Speculation that Trawick was planning to pop the question first emerged online this week, when a source claimed that he asked Spears's father Jamie for permission to propose.
Trawick called into Access Hollywood Live on Friday (December 16) to confirm that Spears has accepted his hand in marriage.
"Yes, we are engaged," Trawick said, beaming that he is "over the moon, as [is] she".
A friend of the couple previously told Us Weekly that Spears accepted Trawick's marriage proposal during a private meal on Thursday (December 15).
The insider also said: "This is something they've both wanted for a long time. It's a way to cement their family. They're both extremely happy and can't wait to become man and wife."
Spears first hinted at the engagement in a Twitter message earlier today (Friday) when she revealed that Trawick had given her a very special present.
She tweeted: "OMG. Last night Jason surprised me with the one gift I've been waiting for. Can't wait to show you! SO SO SO excited!!!! Xxo."
Spears first tied the knot to childhood friend Jason Allen Alexander in 2004, but the marriage was annulled 55 hours later.
In 2004, the star married dancer Kevin Federline and later gave birth to the couple's children Sean Preston Federline and Jayden James Federline.
Spears filed for divorce from Federline in November 2006, with their marriage legally ending several months later in July 2007.
She first confirmed her romance with Trawick, her former agent, in May 2010. The pair denied previous marriage rumours earlier this year.
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