Miley Cyrus, Liam Hemsworth not engaged, she tweets

Did Liam Hemsworth put a ring on it?

According to Miley Cyrus, the answer is no. The actress shot down these rumors with a tweet on Monday:

"I'm not engaged," the 19-year-old tweeted "I've worn this same ring on this finger since November! People just wanna find something to tal[k] about! It's a topaz, people!"

Speculation that the pair was getting married began over the weekend when singer-actress Miley Cyrus posted a tweet about her manicure that displayed a photo showing a good-sized diamond ring on her left hand.

"I am sooo obsessed with @jennahipp nail foundations! It looks so chic and classic!" Cyrus, 19, wrote to her Twitter followers -- at least two of whom replied by asking whether the picture meant she is engaged, although those posts had been removed by late Sunday afternoon.

She was also photographed Saturday wearing the ring when she and Hemsworth, 22 -- star of "The Hunger Games" and the younger brother of "Thor" star Chris Hemsworth -- attended boxing legend Muhammad Ali's Celebrity Fight Night XIII event in Phoenix, according to People and Us Weekly magazines.

Cyrus and Hemsworth met while filming the Nicholas Sparks coming-of-age romantic drama "The Last Song" (2009). Hemsworth also appeared in Cyrus' accompanying music video, "When I Look at You."

They announced their breakup in August 2010, but less than a month later the two were photographed together running errands and spending time at Cyrus' Toluca Lake, Calif., home.

The on-again off-again couple were off again by November 2010, but Cyrus' musician brother Trace told Us in June that the two had reconciled. In January, Cyrus gave Hemsworth a puppy for his 22nd birthday.

Cyrus' next film is the ensemble comedy "LOL," due out May 4, followed by a starring role in the action-comedy "So Undercover." Hemsworth next appears in the independent drama "AWOL," about a Vietnam War-era soldier.