Countries most vulnerable to climate change expressed anger today at developed nations who are rethinking the timetable for concluding a binding global treaty.

Negotiators are working to hammer out a draft political agreement in which rich nations would make hard pledges to reduce emissions and to finance aid for the world's poorest countries. Work on a more formal treaty would continue.

Some delegates warned, however, that a watered-down deal could face trouble at Copenhagen next month.

A bloc of 43 island nations said in a statement that the only thing lacking is political will by leaders of the world's industrial countries to conclude an ambitious and legally binding pact in Copenhagen.

The islands, along with the world's least developed countries, are demanding steep emissions cuts from rich countries beyond what they are aiming for.