Mrs Clinton said those with interests in the Arctic should have been invited
Hillary Clinton has criticised Canada for failing to invite indigenous groups and Scandinavian countries to talks on the future of the Arctic.
The US secretary of state said everybody affected by the changes brought about by climate change in the Arctic should have been included.
She was speaking at the start of the meeting near Ottawa.
Canada invited Russia, Norway, Denmark and the US to the meeting, but not Sweden, Finland or Iceland.
Mrs Clinton said all those "who have legitimate interests in the region", including indigenous peoples, should have been invited to the conference.
"We need all hands on deck because there is a huge amount to do, and not much time to do it.
"What happens in the Arctic will have broad consequences for the Earth and its climate.
"The melting of sea ice, glaciers and permafrost will affect people and ecosystems around the world," she said.
Canadian Foreign Affairs Minister Lawrence Cannon said the representatives who had attended the conference had agreed on the need for "deepening cooperation" in the Arctic, in view of increased shipping in the region
The Arctic Council - an intergovernmental group of Arctic states and groups representing the indigenous Inuit people - meets twice a year to discuss regional issues.
Some concern has been expressed that the five coastal states at the Canadian meeting were forming an "inner core" at the expense of other parties.
But Mr Cannon said the meeting did not intend to "to replace or undermine the Arctic Council".