Requiring migrants to take a test to prove they understand what the government describes as Kiwi values would be a useful exercise in affirmation, Christopher Luxon said on Thursday.

Speaking with RNZ's Morning Report, the prime minister was asked why do we need a citizenship test when the existing procedure already requires them to commit to understanding those responsibilities and privileges.

"It's probably not a bad thing to remind people that things like freedom of expression and freedom of speech and women having equal rights... all those kinds of things are actually to have them positively affirmed for a test like that is probably a good thing," Luxon said.

Yesterday, on May 6, internal affairs minister Brooke van Velden announced those applying for New Zealand citizenship will have to sit a formal test to demonstrate their knowledge of civic rights and responsibilities.

The test, due to be in place in the second half of 2027, will be conducted in person and use a multi-choice format. Applicants will need to score at least 75 per cent to pass.

But critics are wondering if the whole exercise is even required. "It's a solution without a problem," immigration lawyer Pooja Sundar told RNZ.

"Are people currently, who are New Zealand citizens, not sharing these values? Is there any data showing that knowing these things makes people a better citizen?"

On Thursday, Luxon said New Zealand wasn't an outlier in rolling out such a test.

"On balance, it's not dissimilar to what...it's very, very similar to what the UK and Australia have been doing for years."

The interviewer then pointed out to Luxon that his government has campaigned on not introducing unnecessary regulations or red tape.

"Why would you want to make it more difficult for these skilled workers?" she asked.

The prime minister said he didn't "think there's any harm".

I think that's going to be self-funded and actually at the end of the day, very similar to the UK and Australia and not a bad thing to make sure people have positive assurance that they understand that, you know, basics like equal rights for women and free speech is important stuff."

Announcing the policy yesterday, minister Velden said the move was aimed at strengthening the existing requirement under the Citizenship Act that applicants have sufficient understanding of the “responsibilities and privileges” of being a New Zealand citizen.

“Citizenship is a commitment to our shared responsibilities and privileges. By ensuring applicants understand these, we strengthen what it means to be a citizen of New Zealand,” she said.

Currently, applicants meet that requirement by signing a declaration.

Under the new system, applicants will instead need to demonstrate their knowledge through testing. 

Topics are expected to include the Bill of Rights Act, human rights, democratic principles, the structure of government, voting rights, and rules around travel to and from New Zealand, as well as certain criminal offences.