John Travolta and Olivia Newton-John became friends on the set of "Grease" in 1978, and their friendship is still going strong.

More than 40 years after they became friends, the iconic duo reunited on Friday at Beverly Hills in Los Angeles in honour of "G'Day USA: Standing Together" event. John Travolta and Olivia Newton-John dressed up as their iconic musical characters Danny Suko and Sandy Olsson for the occasion.

Travolta opened up to US Weekly about meeting his long-time friend, and said: "It was one of the highlights of our lives to see the joy of people's unrequited love happening from 40 years of people waiting to be with us."

"I think we love each other and when you love someone you stay in touch," the 65-year-old said about Olivia.

The "Saturday Night Fever" actor further gushed about getting back in the 50s getup that included his famous T-shit Birds leather jacket and said: "It was awesome. For whatever reason, like, the bald head suits me, so does that '50s getup. So either I'm gonna go bald or wear a Danny '50s hairdo. It suits my appearance."

The actor was there to support the "Xanadu" actress throughout her numerous battles with her health. The 71-year-old actress has overcome breast cancer twice but is now again battling the chronic disease for the third time along with a tumor she has at the base of her spine.

Grease movie
Paramount Pictures

Talking about Olivia's struggle with her health, John said: Olivia is a survivor and she's smart and she's got a lot of life in her. I think she looks at it from the glass half full, always, and that's her beautiful, natural approach toward life and I think we all need to do that."

They were last photographed together in December in Florida for a "Meet N' Grease" sing-along event. Earlier in August, John revealed to US Weekly that he and Olivia "text each other all the time" and often catch up on dinner outings.

"She's doing great. And she looks fantastic! I'm so proud of her. I mean, have you ever seen anyone look like that?," he told the outlet.