Foreign Affairs Minister Nanaia Mahuta has announced New Zealand is suspending its bilateral human rights dialogue with Iran.

The decision comes as protesters across Iran have been demonstrating against the government following the death of 22-year-old Mahsa Amini while being held by the country's morality police.

Iran's law enforcement has been violently cracking down on protesters, with demonstrators being beaten, arrested and sometimes killed.

Mahuta said the decision was made to send a clear message to Iran that what is happening is not okay.

"This decision sends a strong signal that bilateral approaches on human rights are no longer tenable with Iran when they are denying basic human rights and violently suppressing protests of those who stand up to them," she said.

"Recent events continue to show Iran's position on human rights is deteriorating, not improving.

"Aotearoa, New Zealand continues to be appalled by the use of force by Iranian authorities in response to peaceful demonstrations following the death of Mahsa Amini last month."

Mahuta went further to condemn Iran's treatment of women. She announced New Zealand has added its name to a joint statement with women foreign ministers of 12 other nations to condemn the violent actions which led to Amini's death and to reiterate calls for an independent investigation into authorities' use of force and the repression of demonstrations.

She said that separately Prime Minister Jacinda Ardern has signed an open letter coordinated by a global collective of women - which includes Michelle Obama, Hillary Clinton, Christine Lagarde and Malala Yousafazi - calling on UN Member States to remove Iran from the UN Commission on the Status of Women.

"Violence against women, girls or any other members of Iranian society to prevent their exercise of universal human rights is unacceptable and must end. This is a difficult time for the people of Iran," Mahuta said.

Mahuta said New Zealand has a track record of holding Iran to account at the UN Human Rights Council.

"New Zealand has repeatedly called on Iran to show restraint and to guarantee and protect the rights of its people. We have in the past sought to raise our concerns over human rights in Iran bilaterally. But for this to be effective and credible, it must be accompanied by a willingness to listen and to change," she said.

The announcement comes after weeks of activists calling for the Government to take more decisive action on the situation in Iran.

On Breakfast this morning, Ardern rejected accusations the Government hadn't taken a strong enough position against the violent crackdown on anti-regime protests.

"At the risk of sounding defensive, we were very clear in our position.

"We condemned what happened; we continue to condemn the retaliation that we saw in response to the protests," she said.

"We do, however, continue to look at what more we can do."

New Zealand and Iran had established the Human Rights Dialogue in 2018 with the hope of advancing human rights issues and concerns in the Middle Eastern country.