Teen star Miley Cyrus is engaged to marry her actor boyfriend Liam Hemsworth.

The 19-year-old singer/actress, who shot to fame on U.S. TV show Hannah Montana, has been dating Aussie star Hemsworth for three years.

They met in 2009 on the set of "The Last Song," in which they co-starred, and split briefly in 2010 before reconciling a month later.

Cyrus tells People.com, "I'm so happy to be engaged and look forward to a life of happiness with Liam."

Hemsworth proposed last Thursday and has given his fiancee a 3.5-carat diamond ring by jeweller Neil Lane.

Cyrus had hinted at the happy news in the days following the proposal in a series of posts on Twitter, in which she wrote, "heaven is a place on earth", "excited for a healthy & happy week", and "I love you more today than yesterday but I love you less today than I will tomorrow."

Just hours before the engagement was announced on Wednesday (06Jun12), she tweeted, "Life is beautiful."

The "Party in the U.S.A." hitmaker previously dated model Justin Gaston for nine months but ended the relationship in 2009 shortly before travelling to Georgia to film "The Last Song."