RAROTONGA, Cook Islands -- China, New Zealand and the Cook Islands announced a new partnership that will deliver an improved water mains system to the people of Rarotonga, the Cook Islands' main island.

It is the first time China and New Zealand have worked together on a major development initiative in the Pacific.

"This major infrastructure project will improve water quality and address health and sanitation issues in Rarotonga," New Zealand Prime Minister John Key said.

"Ensuring communities and businesses have access to clean drinking water is critical and will improve livelihoods and promote economic growth," Key said in a statement.

"It will mean a better quality of life for the people of the Cook Islands and provide an improved tourist experience for visitors."

The total cost of the new project, which will see reticulated water mains laid across Rarotonga, is approximately NZ$60 million ($48.01 million).

New Zealand would provide NZ$15 million to assist the Cook Islands government, while China would give about NZ$32 million by way of a loan.

The project was part of an on-going commitment by the Cook Islands government to improve its water and sanitation infrastructure and built on the work New Zealand had already carried out to improve the water quality of the Muri lagoon, on the east of the island, said Key.

New Zealand would provide on-going support for both water and sanitation and had earmarked a further NZ$10 million for related initiatives in the Cook Islands.