Miley Cyrus and Liam Hemsworth are 'so happy' says her father Billy Ray... as he reveals he is ready to perform any wedding duties

Miley Cyrus and her beau Liam Hemsworth are 'so happy' together, according to the singer's father Billy Ray.

The couple, who rekindled their romance this year, have sparked rumours that they are planning to walk down the aisle after Miley was spotted wearing the engagement ring he gave her the first time.

And rather than confirm whether his daughter's engagement is back on, Billy Ray instead spoke about how things are going well for the on-again couple.

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Back together? Miley Cyrus and her beau Liam Hemsworth (pictured together) are 'so happy', according to the singer's father Billy Ray

The country singer, 54, also said he was ready to perform any duties at their wedding, jokingly suggesting he could be the butler, or the preacher.

'Here's what I do know. They're so happy. That's the main thing,' Billy Ray told E! News.

'Miley and I, we always had this slogan—'If you ain't happy, it ain't working.' Just seeing these—I still call 'em kids—these two kids happy, that's all that matters.' 

See Miley Cyrus updates as Billy Ray says she and Liam Hemsworth are 'so happy'

Ready to step in: Billy Ray Cyrus (left) said he was ready to perform any duties at their wedding

Figure-hugging: Miley wore a supertight grey all-in-one as she headed to board a helicopter with beau Liam earlier this month

Miley and the Hunger Games star have not yet commented about their rekindled relationship, but her father said he would be at the ceremony if they did choose to marry.

'If any of my kids decide that they're gonna have a wedding of any kind, whatever role they want me to play, I'll be there, you know what I mean?' he said.

'They want me to be the butler—that's fine. Whatever they choose. I might make a good preacher.' 

Liam acknowledged that they were back together in a recent interview, but said he didn't want to talk about his private life.

He told Entertainment Tonight: 'Everyone's happy. I'm happy. Yeah... I just find it's easier to not talk about my personal life because usually I say the wrong thing, so it ends up just complicating things more. So, I feel like it's better not to talk about it.'

Rumours began circulating at the start of the year that the pair were planning to walk down the aisle after the Wrecking Ball singer was spotted wearing her 3.5 carat diamond engagement ring.

Liam and Miley first got engaged in 2012 after meeting on the set of The Last Song in 2009.

After an on-off relationship, they ended their engagement in 2013. 

'If you ain't happy, it ain't working': Billy Ray opened up about his relationship with Miley

Back on? Liam acknowledged that they were back together in a recent interview, but said he didn't want to talk about his private life

The pair have been spotted in Australia in recent months, with Miley ringing in 2016 with the Hemsworth brothers in Bryon Bay, on Australia's North Coast.

Earlier this year they were spotted looking loved up at a friend's wedding, which was held at Chris' Byron Bay mansion with video later emerging of Miley singing at the reception, dedicating a song 'about the person' she loves.

The pair often hang out with the Hemsworths, who often travel together after mum Leonie and dad Craig retired.

He added to ET: 'My (parents) are both retired now, so they're able to kind of travel with us and hang out and be in our lives more and more, which is good.

'For the first few years I was in America, I'd only see my parents once or twice a year, and that was really hard, but we manage to see each other a lot more now.'