The current Government wants to raise the age of superannuation entitlement from 65 to 67, starting in 20 years' time.

The changes under a National-led Government will be phased in from 1 July 2037 and will not affect anyone born on or before 30 June 1972.

"New Zealanders are healthier and living longer so adjusting the long-term settings of NZ Super while there is time for people to adapt is the right thing to do," said Prime Minister Bill English.

Watch as the Prime Minister gives his weekly briefing to journalists. Source: 1 NEWS

Mr English said the Government was announcing the change now so that political parties "can debate superannuation transparently in the lead-up to the election".

The Government is also proposing to double the residency requirements for NZ Super so that applicants must have lived in New Zealand for 20 years, with five of those after the age of 50.

People who are already citizens or residents will remain eligible under the existing rules.

Finance Minister Steven Joyce said "greater life expectancy is course positive but it does drive up the cost of NZ Super".

"While New Zealand has a more affordable scheme than most countries, the increasing costs would require future trade-offs - either restricting spending increases in areas like health and education, or increasing taxes," he said.

The previous Prime Minister John Key had refused to raise the age.

Mr English this morning refused to reveal details on a policy reset for superannuation.

He announced that reset was underway in a media interview at the weekend.

Other settings such as indexing NZ Super to the average wage and universal entitlement without means testing will remain unchanged. The age that KiwiSaver funds can be accessed will remain at 65.

The Govt said in a media statement that average life expectancy in New Zealand had increased by 12 years over the past 60 years.

The change in the age will be legislated for next year.

The Government said the proposed changes to the age of eligibility and the residency requirements are estimated to save the Government $4.0 billion annually once the changes are fully in place.

The residency changes will cover people who arrive in New Zealand after the legislation is passed.

Mr English said the Government has been doing work on the Superannuation policy since he became Prime Minister and caucus discussed it at the one-day caucus meeting in early February.