The Huvalu Forest Conservation area, which contains some of the world's most threatened flora and fauna, is also protected.

Niue now had a dark-sky community and two dark-sky sanctuaries, said Tourism Niue chief executive Felicity Bollen.

"It's a huge undertaking for us because it shows clearly to the rest of the world that we take very seriously the sustainability of our environment and culture and how precious we hold the land, the sea and now the sky."

Celebrations were held on Sunday (local time) to mark the island's milestone achievement.

Niue now has dark-sky status from the southern edge of Mutalau Village to the northern edge of Hakupu Village.

Both the marine reserve and forest sanctuaries cover 75 percent of the island's land mass, Ms Bollen said.

The initiative, championed by Niue Tourism, received support from the government and community with the whole island coming together to support the project and make the changes.

Andre Siohane, of the Ministry of Infrastructure in Niue, said the government was committed to the protection, management and enhancement of the nation's dark skies.

"Some of the significant measures undertaken by the government include full streetlight replacement for the entire island and the upgrading of domestic private lighting," he said.

Ms Bollen said dark skies and dark-sky tourism became one of the hottest trends last year.

She said people could travel to Niue to admire the dark sky, and learn about the culture and the mythology from the people who lived on the land.

"Niue is always looking for tourism opportunities, tourism products, and services which have a minimal, negative impact on the environment and culture," she said.

"Dark sky absolutely meets that criteria."

Ms Bollen said they had trained "dark-sky ambassadors" who had set up business in the villages and would take tours around the country.

That was a great economic contributor for Niue and for small businesses, and Niue was proud to receive such an important acknowledgement from the IDA.