Two climbers have been rescued after being trapped for two nights on Mt Tasman in New Zealand's Southern Alps.

The men, a 23-year-old from Australia and a 25-year-old from Britain, were found by searchers on Monday morning in a crevasse area near the summit of the mountain, police say.

Inspector Dave Gaskin says the pair were reported missing after they failed to return from their climb on Saturday.

Severe weather conditions in the mountains over this time raised concerns for their welfare.

The climbers have been taken to Mt Cook village for medical assessments, but initial reports are that they are wet and cold, but uninjured.