John Travolta leads tributes to Olivia Newton-John

John Travolta has paid an emotional tribute to his late Grease co-star Olivia Newton-John.

The legendary actress/singer passed away peacefully at her ranch in Southern California on Monday morning following a battle with cancer. She was 73.

Taking to Instagram, Travolta was one of the first to honour Newton-John, whom he famously appeared alongside in the 1978 film Grease.

"My dearest Olivia, you made all of our lives so much better. Your impact was incredible. I love you so much," he wrote alongside a photo of the star. "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!"

Travolta and Newton-John, who performed the hit duets, You're the One That I Want and Summer Nights, in Grease, reunited and dressed up as their characters Danny and Sandy for a special singalong event held in Florida back in December 2019.

In addition, a number of other celebrities have honoured Newton-John.

"Too young to leave this world. May she RIP," wrote Barbra Streisand on her Instagram page, while singer Richard Marx tweeted: "My heart is broken. Rest now, sweet friend. You were as kind and loving a person as there's ever been. I'll miss you every day."

Elsewhere, actress Yvette Nicole Brown expressed her sadness over the star's passing.

"Olivia Newton-John has died. That's it. I'm done guys. Heartbroken doesn't even BEGIN to cover it. I ADORED her. I hate this so much. She was only 73. What is going on?!" she wrote.

And George Takei described Newton-John as a "great" artist and remembered her performance in 1980 movie Xanadu.

"We have lost a great, iconic artist in Olivia Newton-John, gone too soon from us at age 73. I trust she is now in the great Xanadu beyond. Know that we are forever hopelessly devoted to you, Olivia. Rest in song and mirth," he wrote.

Newton-John was first diagnosed with breast cancer in 1992, and while she recovered at the time, the disease returned in 2017.

She is survived by her 36-year-old daughter Chloe Lattanzi and husband John Easterling.