John Travolta pays tribute to dear friend Olivia Newton-John following her passing

John Travolta has paid tribute to his dear friend Olivia Newton-John following her passing today, aged 73.

The duo starred in the classic movie Grease together in 1978 but have remained the best of friends over the years.

"My dearest Olivia, you made all of our lives so much better," he wrote on Instagram alongside a throwback pic of the Aussie star. "Your impact was incredible. I love you so much. We will see you down the road and we will all be together again. Yours from the first moment I saw you and forever! Your Danny, your John!"

READ MORE: Olivia Newton-John's daughter Chloe Lattanzi shares tribute after her death at 73

Back in 2019, the former co-stars reunited as they recreated their iconic Grease characters, Danny and Sandy, for a sing-along of the movie and a Q&A session at the Coral Sky Amphitheatre in Florida. 

READ MORE: Tributes flow for beloved Aussie Olivia Newton-John as she loses battle with breast cancer, aged 73

It was the first time they revisited their characters since they first made the movie more than 40 years ago Newton-John.

"First time in costume since we made the movie! So excited," she wrote on Instagram at the time. 

Speaking to Entertainment Tonight in 2020, Newton-John said she will always hold Travolta close to her heart.

"He's a dear friend and he always will be," she told the outlet. "We formed great bonds making [Grease] as you can imagine and it's always amazing to me that every… It's 40 years now and every 10 years I thought… It's going to fade away now but it just gets bigger and bigger and it seems to find a younger audience all the time it's really quite amazing."

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And Travolta only has good things to say about their decades-long friendship too, saying they go out of their way to keep in touch.

"We text each other all the time," he told Us Weekly in 2019. "It's wonderful ... If I go to see her in her show, we go backstage and hang out, and I watch the show and all that. If I go to see her personally, we usually have dinner and catch up."

Newton-John passed away this morning following a 30-year battle with breast cancer. She was 73.

READ MORE: From country singer to global star, Olivia Newton John's incredible rise to fame