Considered a global icon and an inspiration to women around the globe, Ms Ardern has been appointed to dual fellowships at the Harvard Kennedy School.

The 42-year-old will serve as the 2023 Angelopoulos Global Public Leaders Fellow and a Hauser Leader at the prestigious university's Center for Public Leadership from this autumn.

"Jacinda Ardern showed the world strong and empathetic political leadership," Dean Douglas Elmendorf said in statement.

He added Ms Ardern will "bring important insights for our students and will generate vital conversations about the public policy choices facing leaders at all levels."

Ardern was just 37 when she became prime minister in 2017.

In January, she shocked New Zealanders by announcing she was stepping down from the role after more than five years because she no longer had "enough in the tank" to do it justice.

She had been facing increasing pressures over the likes of her handling of the COVID-19 pandemic, which was initially widely lauded but later criticised by those opposed to mandates and rules.

Speaking about the Harvard opportunity, she said she sees it as a chance to not only share her experience with others, but also to learn.

"As leaders, there's often very little time for reflection, but reflection is critical if we are to properly support the next generation of leaders," she said.

The former prime minister's time at the Cambridge, Massachusetts, university will also include a stint as the first tech governance leadership fellow at its Berkman Klein Center for Internet & Society.

The center has been a key partner as New Zealand has worked to counter violent extremism online after a white supremacist gunman killed 51 people in two mosques in Christchurch in 2019, Ardern said.

The gunman live-streamed the killing on Facebook for 17 minutes before the video was deleted.

Ardern launched the Christchurch Call - a community of more than 120 governments, online service providers, and civil society organisations - with French President Emmanuel Macron two months after the shooting.

The initiative's goal is to eliminate terrorist and violent extremist content online.

It prompted more than 50 countries to join, including the United States, Britain, Germany and South Korea, as well as technology firms such as Facebook parent company Meta, Amazon, Google, Microsoft, YouTube, Zoom and Twitter.

Read more:
Jacinda Ardern gets standing ovation as she delivers farewell speech to parliament
Chris Hipkins: Who is Jacinda Ardern's replacement as New Zealand's PM?
Jacinda Ardern 'driven from office' by unprecedented 'hatred and constant abuse'

"The Center has been an incredibly important partner as we've developed the Christchurch Call to action on addressing violent extremism online," Ardern said.

She added the fellowship will be a chance to not only work with the facility's research community, but also to work on the challenges around the growth of generative AI tools.

Jonathan Zittrain, co-founder of the Berkman Klein Center, said it's rare for a head of state to be able to immerse deeply in a complex and fast-moving digital policy issue.

"Jacinda Ardern's hard-won expertise - including her ability to bring diverse people and institutions together - will be invaluable as we all search for workable solutions to some of the deepest online problems," he said in a statement.

Ardern said she planned to return to New Zealand following the fellowships.