The surging costs of climate change-driven destruction have made vulnerable nations poorer by about one-fifth, 55 such countries said Wednesday, as fears grow that U.N. discussions on money for states to repair and avoid harm could become a "talk shop."

"Loss and damage" caused by more extreme weather and rising seas is a key issue at midyear U.N. climate talks in the German city of Bonn, as negotiators launched a three-year dialogue this week on a topic that has long divided rich and poorer economies.

The "Glasgow Dialogue" emerged after a push for a new loss-and-damage fund for vulnerable countries floundered at the U.N. COP26 summit in Scotland last year due to resistance from donors including the United States and some European governments.