New Zealand's government said Sunday it plans to reverse a five-year-old ban on new oil and gas exploration, igniting a backlash from political opponents and environmental groups.

A bill to be introduced this year would end the ban that has only allowed exploration for new petroleum on some onshore fields in the country's North Island.

Resources Minister Shane Jones claimed the ban had stymied international investment and left the country's energy security compromised.

"Natural gas is critical to keeping our lights on and our economy running, especially during peak electricity demand," Jones said in a statement.

"When the exploration ban was introduced by the previous government in 2018... it also shrank investment in further development of our known gas fields which sustain our current levels of use."

Greens co-leader Chloe Swarbrick said the government was "tipping oil and gas onto the climate crisis fire".

"We can have a more sustainable and efficient economy by prioritising clean energy that works with the environment, not against it."

Jones said the ban would mark the start of a "suite of proposed amendments" designed to spark investment, saying the petroleum and minerals sector contributed US$1.2 billion to GDP in 2020-21.

He said the government plans to ease how petroleum exploration applications are tendered.

The announcement comes a day after thousands protested in New Zealand's biggest cities, objecting to another government initiative to boost the economy.

The "Fast Track Approvals" bill would allow several environmental regulations to be bypassed and the consenting process sped up for major infrastructure projects.