A 16-year-old boy has been charged with brutally assaulting a wheelchair-bound Canadian at Mt Druitt, Sydney. He has since been remanded in custody.

The man was waiting alone for a train on the platform of Mt Druitt Railway Station about 11pm Tuesday when he was allegedly assaulted by two males, the New South Wales police said. One of the alleged offenders was arrested a short time later.

The youth, from Doonside, was charged with causing grievous bodily harm with intent, and robbery armed with offensive weapon causing wounding/grievous bodily harm.

He appeared Parramatta Children’s Court today and was refused bail to re-appear on 8 April.

The victim remains in Westmead Hospital with head injuries.

Police are appealing for anyone with information about the incident, or the identity of the second person.

The 35-year-old was at Mount Druitt station in Sydney's west on Tuesday night on the way home after seeing friends play in a band when two youths began attacking him. The Canadian was punched in the face as he entered a lift.

The "unprovoked" incident lasted about three to five minutes and was captured on security video and witnessed by a railway station employee who alerted police, said Superintendent Wayne Cox.

The teenagers had tried to take the man's possessions, he said and added it was probably one of the most serious attacks he had ever seen.

"It's a cowardly, horrendous, horrific thing that they've done," said the Canadian’s girlfriend Kristin Sharrock. He was visiting her in Australia.