Prime Minister Jacinda Ardern has banned future offshore oil and gas exploration in New Zealand.

The only exploration likely to be contemplated by the new Government is on-shore exploration limited to energy-rich Taranaki.

"We're protecting industry and protecting future generations from climate change," said Ardern.

"This is a responsible step, which provides certainty for businesses and communities that rely on fossil fuels."

The more than 30 existing permits, 22 for offshore oil and gas exploration, are unaffected by today's announcement, Energy Minister Megan Woods said. If those permits, which cover 100,000sq km are continued or taken up, exploration will continue for more than a decade.

Ardern and the ministers are expected to outline plans for their version of a managed transition towards a carbon-neutral economy by 2050 and a goal of achieving 100 per cent renewable electricity buy 2035.

The Government had already postponed any decision about lock offers this year - a competitive way by which oil and gas exploration permits have been issued for the past few years.

And Ardern personally accepted a Greenpeace petition at Parliament this month to ban all oil and gas exploration.

But some had been holding out hope that the Government would still accept bids for exploration on a case by case basis.

Today's decision put paid to those hopes.

National leader Simon Bridges, a former Energy Minister, described Ardern as "reckless" last month for suggesting an end to oil and gas exploration in New Zealand.

He also described Ardern's decision to receive the Greenpeace petition as a "political stunt".

"There's a world of difference between changes to block offer and ending all new oil and gas exploration," he said.

"What matters is the words you use. Prime ministers can't be loose with these things. It has a chilling effect. There are thousands of people with jobs here, don't be reckless like that."

Act Leader David Seymour has said any ban on oil and gas exploration would put 11,000 jobs at risk and could harm the environment.

The oil and gas industry created thousands of jobs, contributed $2.5 billion to the New Zealand economy and $500 million to the Government in royalties each year, he said.

"Not only would a ban on exploration make us poorer as a country, it would drive production of oil and gas overseas, which will harm the environment."