Three climbers from the US and Canada are missing after they failed to return from a planned ascent of New Zealand’s highest mountain, Aoraki, authorities said on Tuesday.

The Americans – Kurt Blair, 56, from Colorado, and Carlos Romero, 50, of California – are certified alpine guides, according to the website of the American Mountain Guides Association.

A statement from New Zealand police did not name the Canadian climber, citing the need to notify his family.

The men flew to a hut partway up the mountain on Saturday to begin their ascent and were reported missing on Monday when they did not arrive to meet their prearranged transport after the climb.

Hours later searchers found several climbing-related items believed to belong to the men, but no sign of them, police said.

New Zealand Aoraki Missing Climbers
A tourist takes a photo at a frozen lake at the foot of New Zealand’s highest peak, Aoraki, in the Aoraki/Mount Cook National Park (Mark Baker/AP)

Search efforts did not resume on Tuesday because of deteriorating weather conditions on Aoraki, also known as Mount Cook, with heavy rain and snow forecast.

Operations were unlikely to begin again until conditions improved, expected to be on Thursday.

Aoraki is 12,218ft (3,724m) high and is part of the Southern Alps, the scenic and icy mountain range that runs the length of New Zealand’s South Island.

A settlement of the same name at its base is a destination for domestic and foreign tourists.

The peak is popular with experienced climbers. Its terrain is technically difficult due to crevasses, avalanche risk, changeable weather and glacier movement.

More than 240 deaths have been recorded on the mountain and in the surrounding national park since the start of the 20th century.