An international deal has been reached to prevent commercial fishing in the High Arctic for at least the next 16 years.

"Canada has reached an historic agreement in principle today in Washington, D.C. to prevent unregulated commercial fishing in the high seas of the central Arctic Ocean," Fisheries and Oceans Minister Dominic LeBlanc said in a statement Thursday.

"It's the first time an international agreement of this magnitude has been reached before any commercial fishing takes place on a region of the high seas."

The countries that have signed on include the five nations with Arctic coastlines, as well as China, Japan, South Korea, the European Union and Iceland. Inuit from three countries, including Canada, were also represented at the table.

"It's heartening to see Arctic and non-Arctic countries come together on conservation measures for the future of the Arctic Ocean," said Herb Nakimayak of the Inuit Circumpolar Council Canada.

"The agreement explicitly calls out the importance of considering Indigenous people's knowledge and the importance of our role in the Arctic."

The decision will stand for 16 years and be renewed every five years after that.

It affects Arctic seas that are at least 200 kilometres away from the shores of any coastal states. That amounts to 2.8 million square kilometres of ocean, about the size of the Mediterranean Sea.

Those seas were once frozen year-round. But as climate change continues to reshape the Arctic, about 40 per cent of those waters were open last summer.

Although no commercial fishing exists there now, climate change is affecting where fish live and more of them are shifting north. Scientists and fishers have wondered what those previously inaccessible waters now hold.

The agreement commits the signatories to an extensive science program.

"This is getting ahead of the curve and preventing a problem," said Scott Highleyman of the group Ocean Conservancy, who has been following the talks.

"For the first time, nations have gotten together and said let's prevent the start of unregulated fishing and actually do a joint program of science so we can figure out what's there first. Now, let's get that joint program of science going."

The talks began in 2015. They followed an earlier agreement that was limited to Canada, the United States, Norway, Denmark and Russia.

Highleyman said the speed at which the deal was reached suggests international co-operation is still the norm in the Arctic, even though negotiating countries may disagree in other parts of the world.

"It shows the Arctic is still a place for co-operation," he said.