A New Zealand ultra-runner is attempting to become one of just five people to run across America and Australia in their lifetime.

Nick Ashill is planning to run almost 4000km across Australia - starting April 15 - to raise money for the Asthma and Respiratory Foundation NZ.

Ashill says despite having arthritis in his knees and hips, and titanium rods and screws in his right leg and pelvis, he is more motivated than ever to complete this run.

"Every step I take in April, May and June will symbolise the everyday struggles and challenges faced by those living with a respiratory condition.

"Yes, I want to prove to myself that I can complete another cross-country run, but, more importantly, I want people to know about the cause I am running for."

Ashill's run across Australia comes nearly seven years after he was left for dead in a ditch following an incident during a charity run across the United States.

It was on day 81, when Ashill was struck by a vehicle in what appeared to be a deliberate hit-and-run.

After a long and arduous recovery, he returned to the US in mid-2022 to the scene of the hit-and-run to finish the 5400km run that ended so abruptly.

On April 15, Ashill will start his journey at Cottesloe Beach in Perth and will finish at Bondi Beach in Sydney. He estimates it will take him about 70 days.

"I am not an elite runner. I am just an ordinary person wanting to do something extraordinary," Ashill says.

"Running 5400km across the US was not conventional - Australia will be no different, but what drives me is a yearning to help others living with respiratory disease.

"The memory of my mum and the fight she endured every day to breathe is a constant reminder of the importance of the Foundation’s work."

Ashill lost his mother to the rare lung disease, idiopathic pulmonary fibrosis (IPF), in 2015. IPF affects about 3 million people worldwide. There is no cure.

Foundation Chief Executive Ms Letitia Harding says Ashill’s commitment to honouring his mother’s memory by supporting others with respiratory diseases is admirable.

"Losing a loved one is never easy, but Nick continues to show strength and determination in his bid to help others.

"We are grateful for his ongoing support in our mission to help 700,000 Kiwis living with a respiratory condition in New Zealand."

Ashill's run is supported by Friends of the Foundation Silver partner, Comfortech.

To support Nick's incredible effort, visit www.nickrunsaustralia.org.nz