GERMAN Chancellor Angela Merkel refused yesterday to commit to a deadline to shut down coal-burning power plants, despite demands by environmentalists as she addressed UN climate talks.

Speaking at the COP 23 climate summit in Bonn, Ms Merkel said there would be “hard discussions” between her Christian Democrats, the Greens and the liberal Free Democrats on the issue.

The Chancellor admitted coal use was part of the reason why Germany would miss its 2020 greenhouse gas emissions targets. Germany generates 40 per cent of its electricity from coal.

The German Greens had previously said they’d drop their pledge to set an end date for coal use if it got them into government.

Meanwhile, masked environmental activists forced the partial shutdown of the Weisweiler coal plant west of Bonn by climbing onto conveyor belts.

Operator RWE had to stop running two of the four generating units for lack of fuel.

And Greenpeace, which protested at the same plant on Saturday, said 14 of its activists had protested on a coal ship on the River Rhine, laying out a banner reading: “Merkel's dirty secret: coal” as the vessel passed the conference venue.

Inside the summit, French President Emmanuel Macron said Europe should make up the funding of the United Nations Intergovernmental Panel on Climate Change that was withdrawn by US President Donald Trump.

German President Frank-Walter Steinmeier suggested that the US might rejoin the 2015 Paris Agreement on climate change in future, reversing Mr Trump’s withdrawal.

“Some who today have left the ship’s bridge for the dinghy may return to our big ship in a couple of years,” he said.

However, UN secretary-general Antonio Guterres warned that the world only had only five years to take action on global warming targets, urging leaders to “show courage in combating entrenched interests.”

“The catastrophic effects of climate change are upon us,” Mr Guterres said. “The voice of small island states that are on the front lines of climate change must be the voice of us all.”