Hamburg: Climate proved the main sticking point at the G20 summit in Germany, with a final joint statement stalling over US demands to include a reference to 'clean' fossil fuels.

German Chancellor Angela Merkel announced an agreement had been reached on Saturday afternoon after aides for the 20 leaders had worked until 2am the night before to finalise a communique.

After overcoming differences on trade – with US officials agreeing to language on fighting protectionism – talks stalled on climate.

The section that needed to be resolved related to US insistence that there be a reference to 'clean' fossil fuels, a European Union official familiar with the negotiations said.