The man was involved in the accident on Tuesday evening.
A statement from the Nauru Coronavirus Taskforce said the man sustained multiple major trauma injuries.
Whilst he was being stabilised in the immediate term by local doctors and nurses, his condition was life threatening.
He remained in need of multiple surgical and medical specialist interventions not available in Nauru.
Arrangements were made by Australia’s Department of Home Affairs to urgently evacuate him by air ambulance for overseas specialist medical treatment last night.