IQALUIT, Nunavut -- The United States assumed leadership of the Arctic Council on Friday and made it clear that the attention of the eight countries that ring the North Pole will shift from economic development to climate change.

"This is not a future challenge," Secretary of State John Kerry told council members, who met in the chamber of the Nunavut legislature in Iqaluit.

"This is happening right now."

Kerry thanked Canada for its two-year term as council chair.

"It's been a very important part of the council's 20-year history and it has given all of us a strong platform on which to build."

He promised to continue key Canadian initiatives, such as the creation of the Arctic Economic Forum, self-selecting northern businesses that meet to discuss opportunities and best practices. The U.S. will also continue Canada's work to reduce black carbon, light-absorbing particulate matter that is a significant contributor to sea-ice melt.

But Kerry left no doubt that the primary focus of the U.S. leadership term will be dealing with the impact of Arctic climate change, which he pointed out affects the entire world. He said the U.S. will also seek to improve environmental protection in the region, including the creation of marine protected areas.

Kerry promised more work on ocean acidification, another result of atmospheric carbon dioxide. The fight against black carbon will include a search for energy alternatives to diesel for northern communities.

"We understand this is ambitious. We have to be ambitious."

Environment Minister Leona Aglukkaq spoke of the pride she felt in being the first Inuk to lead the council.

"It was a great honour for me, as an Inuk, to be the first Arctic indigenous person to serve as chair of the Arctic Council," Aglukkaq told the meeting.

She said the council, which co-ordinates international co-operation and research in the increasingly busy and contested region, must continue to include the concerns and expertise of northerners to inform its work.

Aglukkaq said that she had brought up Canada's displeasure with recent Russian activities with Russian Environment Minister Sergei Donskoi.

"I did have a brief discussion to express our concerns, to state again the we condemn the actions in Ukraine," she said.

Kerry said that despite increased military activity in the Arctic, security issues aren't likely to find their way any time soon onto the agenda of the council, which is forbidden by its mandate to hold such discussions.

"There are legitimate concerns," he said.

"The tricky thing is whether or not that would complicate what thus far has been a very functional process by which we've been able to address social, environmental and other kinds of structural issues.

"To allow that to happen really could deter from the ... overall work of the council itself, which is why the council has regularly tried to steer clear of that."

Kerry said Russian Foreign Minister Sergey Lavrov told him in a recent telephone call that Russia wants the council to continue to function smoothly.

"It is their intent to co-operate with us on the protection of the environment and the agenda we have set forth."

Kerry said there are other places where Arctic security concerns can be discussed.

In his address to the council, Donskoi denied his country is militarizing the North

"Russia sees the Arctic as a territory for dialogue and co-operation," he said. "It's the only way we can achieve prosperity.

"There is no room for confrontation or fearmongering, particularly from forces from the outside. Russia is against politicizing the Arctic."