The world's major fishing nations have agreed a moratorium on commercial fishing in the Arctic Ocean, before it has even become established.

Much of the Arctic was once permanently frozen but global warming means its waters are becoming more accessible.

The deal is expected to last for 16 years while research is carried out into the existing marine ecosystem.

The moratorium was agreed by Canada, Russia, China, the US, the EU, Japan, Iceland, Denmark and South Korea.

It covers an area of about 2.8m sq km (1m sq miles) - roughly the size of the Mediterranean Sea. No commercial fisheries exist in Arctic waters yet.

"This is one of the rare times when a group of governments actually solved a problem before it happened," said David Balton, US ambassador for oceans and fisheries.

"In the future if fish stocks are plentiful enough to support a commercial fishery there, they will be part of the management system and presumably their vessels will have the opportunity to fish for those stocks."

Conservationists applauded the deal.

Trevor Taylor, of the Canadian group Oceans North, said fish and marine mammals that many Arctic communities relied upon would now be protected.