Finance Minister Bill English is not ruling out changes to Working for Families or the student loans scheme as the Government considers how to foot the bill for Christchurch's earthquake recovery.

However Mr English said the Government remains committed to existing infrastructure projects such as Ultrafast Broadband although there may be some "flexibility" as to their timing.

Mr English said it was still early days in assessing the impact of the quake on the Government's finances and the wider economy.

"However we're confident that the economy is resilient and it will continue to rebalance in a direction that is favourable to stronger economic growth later."

Treasury's initial assessment was last week's quake would be three times more expensive than the September quake's $5 billion including Government and private insurer costs, but more a detailed assessment was to be completed and made public later this week.

Most of the Government spending on recovery would be focused on ensuring the welfare of Christchurch's people and on essential infrastructure, roads, water, sewerage and schools.

"We will pay for this by prioritising our spending on Canterbury and it may be the case that we take on a bit more debt in the short term."

However, the Government would continue to be mindful of New Zealand's vulnerability due to its debt "and we will be endeavouring to deal with the impact of the earthquake within the reasonable bounds of the current levels of foreign debt and Government debt".

This latest in a series of shocks underlined the necessity of looking harder at Government's priorities, Mr English said.

The Government had already begun doing that, "and the earthquake simply means it's now absolutely necessary and we need to produce some fairly definitive results from that process".

In that process, the Government had been careful to maintain frontline services and income support for those who needed it and keep a focus on investment in infrastructure on productive investment.

"But we are just going to have to test the limits of it."

Asked whether that meant the Government would now look at areas previously ruled out of bounds such as interest free student loans and Working for Families, Mr English said his Government was not going to rule anything in or out.

"We need to give ourselves the room to find the cash without increasing vulnerability as an economy too much."

As far as big infrastructure projects, "we're not considering changing our approach to any of those".

"There could be issues around timing but that's just simply at the moment a possibility."

In response to Mr English's comments, Labour leader Phil Goff said the Christchurch earthquake should not be used "as an excuse to sell off our valuable assets".

He said cutting financial assistance to families and students in other parts of New Zealand would slow the economy.

"It would be wrong to cut financial assistance to families and students who rely on that support, especially when the cost of living is sky high. That would simply slow the economy down. We must keep money in the pockets of people who will spend it," he said.

"The earthquake is a tragedy. The lives that have been lost will never be recovered and we mourn their passing. But all New Zealanders are prepared to stand together and shoulder the financial burden of the recovery. And given economists are pointing out the Government does not have a debt problem - there is room to move.

"We are in a good position to carry the weight of this tragedy."

State of emergency extended

Civil Defence Minister John Carter has today extended the national state of emergency for a further seven days.

The national state of emergency in New Zealand was declared last Wednesday and is expected to continue for several more weeks, Mr Carter says.

"This declaration ensures coordination and cooperation between central and local resources, and international assistance. Due to the scale of this disaster, the civil defence response is beyond the resources of the local authority," he says.

Two minutes' silence for earthquake victims

New Zealanders today paid tribute to the victims of the Christchurch earthquake with two minutes' silence marking the moment the disaster struck last week.

The shallow 6.3 magnitude quake centred at the port town of Lyttelton struck at 12.51pm last Tuesday, killing at least 154 people, with police expecting the final toll to reach "around 240".

Rescue workers in Christchurch paused in their work to remember the victims of the quake as officials, religious leaders and members of the public gathered throughout the country.

Death toll

Police Superintendent Dave Cliff earlier told reporters the death toll remained at 154.

But Mr Cliff said the number of dead was expected to rise. He said a figure of around 240 was "solidifying" but could still change.

Police would officially release the names of at least three more victims later today, he said.

International help

Foreign Minister Murray McCully said hundreds of rescue workers and millions of dollars in overseas aid had poured into Christchurch in the past week.

More than 900 international personnel from 12 countries are now working with New Zealand search and rescue teams in Christchurch, Mr McCully said.