Environmental campaigners were given some hope that the US may stick to its commitments under the Paris climate change treaty when Rex Tillerson, the US secretary of state, signed a commitment to protect the Arctic and extend scientific co-operation.

He was speaking at the end of a meeting of the eight-nation Arctic Council in Alaska, a consultative body dedicated to sustaining the Arctic.

The members signed a document “noting the entry into force of the Paris agreement on climate change and its implementation, and reiterating the need for global action to reduce both long-lived greenhouse gases and short-lived climate pollutants.”

The representatives also state that they recognise that “activities taking place outside the Arctic region, including activities occurring in Arctic States, are the main contributors to climate change effects and pollution in the Arctic, and underlining the need for action at all levels.”

Temperatures have been rising faster in the Arctic than elsewhere, revealing the acute threat to the region and leading to fears about a wider knock-on effect around the globe.

There have been fears that the council, which is not a formal decision-making body, would be unable even to agree a joint declaration.

Donald Trump, in his presidential campaign, described climate change as a Chinese hoax, but since then there has been a huge debate raging inside the administration about whether to pull out of the Paris treaty, signed in 2015, or to lower the level of US commitments.

Tillerson sought to reassure the international Arctic community, saying “we’re not going to rush” to make a decision, but that the American government would make “the right decision for the United States”.

“We are appreciative that each of you has an important point of view, and you should know that we are taking the time to understand your concerns,” Tillerson said. “The Arctic Council will continue to be an important platform as we deliberate on these issues.”

There were also fears that wider geopolitical tensions will develop in the Arctic as the US, Russia and China battle for oil and gas resources likely to be opened up by the melting of icecaps and unfreezing of waters.

But in their opening remarks, foreign ministers from the world’s eight circumpolar nations instead reaffirmed their commitment to keeping the world’s geopolitical tensions out of the forum’s work, which focuses on environmental issues and sustainable development.

“The Arctic Council is so valuable to all of us, and very much for Canada, [because] it’s where we, the Arctic nations, can set aside issues outside the Arctic and appreciate that we have shared stewardship of this region,” said Canadian foreign minister Chrystia Freeland.

“The US-Russia initiative will make it easier to move equipment, samples and data across borders in the north and facilitate scientific collaboration and sharing.”