Australian actor Liam Hemsworth and U.S. singer Miley Cyrus aren\'t engaged, as some reports have said, sources close to the couple told UsMagazine.com. Hemsworth, 22, and Cyrus, 19, have been dating for more than two years. They met on the set of the 2009 romance \"The Last Song.\" UsMagazine.com said the wedding buzz began when Cyrus was photographed wearing a huge diamond ring on her finger during the weekend. The celebrity news Web site quoted unnamed insiders as saying Hemsworth and Cyrus are not planning a walk down the aisle anytime soon. Cyrus is best known for her work in the Hannah Montana TV and film franchise. Hemsworth is the star of the blockbuster \"The Hunger Games.\"