The confirmed death toll from the New Zealand Christchurch earthquake rose to 145 on Saturday, while the number of missing people remains at more than 200.

Superintendent Dave Cliff said at a media briefing on Saturday that more deaths have been confirmed on Saturday afternoon and a temporary mortuary had been set up at Burnham military camp to identify bodies.

Thirty family liaison teams have been contacting families in New Zealand and overseas.

Officials said Christchurch central city will be closed for months, and in the meantime patrols would monitor the area round the clock.

Christchurch Mayor Bob Parker said that of the 1,000 buildings within the city's four avenues, just 600 were safe to enter.

Between 200 and 250 buildings had been issued with a red sticker, meaning they are unsafe to enter. Some may be in danger of imminent collapse.

New Zealand Prime Minister John Key spent Saturday in the city, meeting search and rescue workers and victims' families.

He said the earthquake might be New Zealand's single most tragic event, and called on New Zealanders to stop and remember those who lost their lives, along with the hundreds who are mourning family and friends.

Key said the government would release an economic support package for Christchurch people on Monday.