The 32-year-old Australian actor addressed his 26-year-old sibling's relationship with the 23-year-old American singer at a Tourism Australia event Monday. Liam Hemsworth and Cyrus have reportedly reconciled after previously ending their engagement.
"I'm happy if he's happy, whatever he's doing in life," Hemsworth said of his brother's rumored romance to Entertainment Tonight . "I can't confirm any of that but, you know, he's smart [and] he's happy."
Hemsworth later claimed ignorance on Australian talk show Today when asked if Liam Hemsworth and Cyrus' engagement is back on. The actor did say he's seen "very inaccurate reports" and "unreliable sources" on the subject.
Liam Hemsworth and Cyrus were together four years before splitting in September 2013. The singer sparked speculation by appearing to wear her engagement ring last week, shortly after being seen with a moving truck outside her ex-fiancé's home.
"Miley is beyond happy to be engaged to Liam again," a source told People magazine. "It might seem sudden, but they have been very close for the past few months. They just wanted to keep their relationship out of the spotlight while they figured things out."
Hemsworth himself is married to Elsa Pataky, and shares 3-year-old daughter India and 22-month-old twin sons Tristan and Sasha with the Spanish actress. The actor will next star in The Huntsman: Winter's War with Emily Blunt, and is also slated for the Ghostbusters reboot.