Liam Hemsworth and Miley Cyrus step out at "Paranoia" premiere

Liam Hemsworth was on the red carpet Thursday for the Los Angeles premiere of his film "Paranoia," with fiancee Miley Cyrus by his side.

The engaged couple, who have been at the center of split rumors for months, stepped out together for their first joint red carpet appearance in more than a year (their last one was June 2012).

Hemsworth, 23, wore a dark suit, while Cyrus, 20 donned a knee-length leather Proenza Schouler dress.

But despite their united front, one report says the couple wasn't exactly cozy during the premiere.

"Miley and Liam acted like they didn't even know each other the entire night," a source told Us Weekly. "She was wearing her ring but they acted as if they were strangers."

The duo has faced an onslaught of rumors about their relationship status in recent months, with reports saying the couple had broken up or was on the rocks.

When asked during a "Good Morning America" appearance last month whether her wedding is still on, Cyrus responded, "I'm wearing a ring, so..."

Hemsworth's "Paranoia," which also stars Harrison Ford, Gary Oldman and Amber Heard, arrives in theaters on Aug. 16.