Police hold grave concerns for three missing climbers on Aoraki Mount Cook.

The climbers, attempting to reach the mountain summit, didn't meet their prearranged transport on Monday morning and were reported missing.

A helicopter and search and rescue teams were unable to find the group that afternoon before bad weather halted the search. It is on hold until at least Thursday.

The climbers have been named as 56-year-old Kurt Blair, 50-year-old Carlos Romero from the United States, and a Canadian national.

Aoraki area commander Inspector Vicki Walker told Morning Report searchers spoke to a party coming down the ridge who said the climbers were going up the route and intending to get to the summit.

Walker could not confirm a report that the men had suffered a fatal fall, but said police had "grave concerns" for the missing party.

Search teams on Monday had found an ice axe and a jacket belonging to the party, who were believed to be ascending via the Zurbriggen Ridge.

Walker said searchers spoke to a party coming down the ridge, who said the climbers were going up the route and intending to get to the summit.

'Not all hope is lost'

Mountain Safety Council chief executive Mike Daisley said the climbing conditions were good at the time the party was expecting to attempt the summit.

The poor weather had come in after they were due out of the area.

Daisley said common hazards on Aoraki Mount Cook were avalanches, glacial crossings, and rockfalls, and there were often icy surface conditions this time of year.

The weather had deteriorated significantly since the weekend, but no avalanches had been reported in the area, he said.

"It's a real tragedy, what looks to be unfolding," he said.

However there had been many examples of experienced climbers such as these surviving by finding snow caves or other shelter.

"Not all hope is lost."

Main photo (Facebook / Silverton Avalanche School): Kurt Blair, 56, is as one of the three missing climbers.