Kurt Blair, 56, and Carlos Romero, 50, from the United States, and a Canadian national, were reported overdue from their planned ascent of the mountain on Monday morning.
"The men flew into Plateau Hut at 3.30pm on Saturday 30 November, planning to summit Aoraki Mt Cook via Zurbriggen Ridge," said Aoraki Area Commander Inspector Vicki Walker.
"They were due to meet their flight out at 8.30am on 2 December but did not arrive for the flight and were subsequently reported overdue.
"A search was initiated yesterday involving the Department of Conservation (DoC) Search and Rescue Team, The Helicopter Line and police.
"During the search, several climbing-related items were located, which are believed to belong to the three men.
"Police have been working with the US and Canadian embassies to inform and support the families of the three men."
Walker said information about the third missing man will not be provided until police have contacted his family.
Weather conditions are likely to prevent any further search activity until Thursday this week. However, Walker said police will continue to monitor and assess the conditions.
