WELLINGTON • New Zealand Prime Minister John Key has unveiled plans to create a South Pacific marine sanctuary the size of France, saying it would protect one of the world's most pristine ocean environments.

Mr Key said the Kermadec Ocean Sanctuary would cover an area of 620,000 sq km about 1,000km off New Zealand's north-east coast.

Announcing the plans at the United Nations in New York on Monday, Mr Key said the area was home to thousands of important species, including whales, dolphins and endangered turtles.

"(It) is one of the most geographically and geologically diverse areas in the world," he said in a statement. "It contains the world's longest underwater volcanic arc and the second deepest ocean trench at 10km deep."

The sanctuary will prevent fishing and mineral exploitation in an area where scientists regularly discover new marine species. Conservation groups applauded the move, saying it added to a network of protected areas in the Pacific that now covered more than 3.5 million sq km.

AGENCE FRANCE-PRESSE