Church officials in New Zealand say the earthquake-damaged iconic cathedral in central Christchurch will be deconsecrated and partially torn down.

Anglican church officials say the 120-year-old building is unsafe after February's 6.1 magnitude quake that killed 182 people and wrecked large parts of the city.

But before any demolition work is carried out, the church has to be pronounced a secular site from a sacred site.

Partial controlled demolition will make the church safe enough for church officials to go inside and retrieve artifacts before a more extensive restoration gets under way.

The Anglican cathedral is a major tourist attraction and a symbol of New Zealand.