A rescue operation is underway for a tramper missing on the Milford Track since Monday. 

Police say the man, who had been intending to climb Devil's Armchair, was reported overdue shortly after midnight on Monday morning, and a search was initiated. 

Before first light today, an aerial search using thermal and night vision technology was conducted. 

The man, who had been intending to climb Devil's Armchair, was reported overdue shortly after midnight on Monday morning, and a search was initiated. Photo / DoC 

A LandSAR dog will continue to search today in the area along the northern part of the Milford Track, a spokesperson said. 

Alpine Cliff Rescue teams will assist to search what was believed to be the man's intended route. 

Further aerial searches will be conducted and extra LandSAR and police search and rescue staff will also join the search efforts today. 

Police said the tramper is experienced in the outdoors. 

- by Devon Bolger, Courtney Winter; NZ Herald