John Travolta is supporting his ''incredible'' friend Olivia Newton-John in the wake of her breast cancer diagnosis.

The 63-year-old star has offered his support to his 'Grease' co-star after she announced she had been diagnosed with metastatic breast cancer that has spread to her sacrum, 25 years after she first fought the disease.

He said in a statement to People magazine: ''Olivia has always been an incredible human being and an inspiration to millions of people. If we all put our intentions for her to get through this - I know her so well - she will feel it, and it will support her. We love her and she loves us.''

It comes after Olivia insisted she is ''confident'' her cancer battle will be a ''positive success story''.

She said: ''I am really grateful for and touched by the worldwide outpouring of love and concern. Thank you.

''I am feeling good and enjoying total support from my family and friends, along with a team of wellness and medical practitioners both here in the US and at my Olivia Newton-John Cancer Wellness and Research Centre in Melbourne, Australia. I'm totally confident that my new journey will have a positive success story to inspire others! Love and light, Olivia.''

Whilst her husband John Easterling added: ''[Her pain] has gone from [level] eight to about a two.

''We both have the same unshakable belief that she's going to have a wonderful success story. We're not trying to be positive. We have an absolute knowingness that we can turn this around.''

Olivia had previously revealed she would be undergoing ''natural wellness therapies'' as well as a short course of photon radiation therapy.

A statement released at the time read: ''The back pain that initially caused her to postpone the first half of her concert tour, has turned out to be breast cancer that has metastasized to the sacrum.

''In addition to natural wellness therapies, Olivia will complete a short course of photon radiation therapy and is confident she will be back later in the year, better than ever, to celebrate her shows.''