Thousands of New Zealand school students plan to go "on strike" on March 15 to support a worldwide day of action over global warming.

The global strike is expected to bring tens of thousands of students on to the streets across Europe, the United States, Australia and other countries.

In New Zealand, national co-ordinator Sophie Handford said protests were being organised in more than 20 towns from Russell in the Bay of Islands to Invercargill.

She said more than 1000 people had said they were "interested" on Facebook sites for protests in each of the four main centres in Auckland, Wellington, Christchurch and Dunedin.

"We are thinking like definitely in the thousands across the country," she said. "If we hit 5000, that will be awesome. If we hit more than that, that will be even better."

Handford, 18, graduated from Kāpiti College last year and found herself acting as the national co-ordinator after she posted on Facebook asking who wanted to be part of a working group to organise local events on the global day of action.

"I had about 30 people on that one post saying me, me, me," she said. "As soon as someone else started it, everyone else was keen to jump in and help."

Handford is a Youth MP representing Mana MP Kris Faafoi at a Youth Parliament meeting in Wellington this week, and many of the other youth MPs have signed up to help.

"They are acting as contacts with all the MPs across the country," she said.

In Wellington, students will assemble at Civic Square at 10am on March 15 and march to Parliament, where youth representatives will speak and then put questions to a cross-party panel of MPs.

The group's "demands" include an immediate ban on exploration and extraction of fossil fuels, regulating emissions from agriculture and supporting the Government's Zero Carbon Act.

In Auckland, the group plans a rally at Aotea Square at midday.

A Youth MP representing New Plymouth-based list MP Andrew Little, Spotswood College Year 13 student Ethan Griffiths, said he was working with students at three other local colleges and hoped to rally at Puke Ariki Landing in the city centre.

"We are hoping to have some musical performances, some young people speaking," he said.

NZ Secondary Principals Council chairman James Morris said school principals would not condone the strike.

"Whilst most principals would support students expressing support for climate change action, they would be reluctant to approve students taking time away from their classes to do so," he said.

"I would expect that most principals would have attendance marked as 'unjustified' as per Ministry of Education guidelines for students who are absent to attend the 'strike'.

"It would be a real sign of the students' commitment to the cause if they chose to give up after school jobs or weekend activities to 'strike' rather than school time."

However Ministry of Education deputy secretary Ellen MacGregor-Reid said awareness of the environment was an important part of the NZ curriculum.

"The NZ curriculum also encourages students to participate and take action as critical, informed and responsible citizens," she said.

"As part of their curriculum schools may want to follow up on their students' interest in social issues such as climate change. This can include discussion of ways they might raise awareness of these critical issues in their communities, including costs and benefits of any proposed action."

The global movement was sparked by a 15-year-old Swedish schoolgirl Greta Thunberg, who decided last August to stay away from school until the Swedish general election on September 9.

She protested by sitting outside the Riksdag (Parliament) every day during school hours with a sign, "Skolstrejk för klimatet (School strike for climate)".

Tens of thousands of students supported her at mass rallies across Germany and Switzerland last month.

A 13-year-old New York schoolgirl Alexandria Villasenor has also been protesting outside the United Nations building on every Friday since December.