Canada is conceding that a treaty on polar bears signed 35 years ago is now forcing it into action on climate change.

All five countries that signed the treaty have ended talks in Norway with an agreement that melting sea ice is now the biggest single threat to the long-term survival of the bears.

The agreement calls for an urgent and effective response to address climate change.

In a document released after the meeting, Canada has also agreed that industrial development in polar bear habitat must be carefully monitored and controlled.

The agreement came out of two days of talks between Canada, the United States, Russia, Denmark and host Norway.