Former U.S. President Barack Obama called for rich nations to end years of deadlock with developing countries over cash for climate change on Monday, while criticizing China and Russia for their "lack of urgency" in curbing emissions.

At the start of the second and final week of the U.N. climate talks in Glasgow — known as COP26 — ministers got down to the detail of trying to honor promises to pay for climate-linked losses and damages, and to address how to help nations adapt to the devastating effects of climate change.

"We have to act now to help with adaptation and resilience," Obama told a meeting of island nations at the summit, adding that his views on the immediacy of the threat had been shaped by his experience growing up in Hawaii.