BONN, Germany (AP) — World leaders arrive at the global climate talks in Germany on Wednesday to give the negotiations a boost going into the final stretch.

Attention will focus in particular on German Chancellor Angela Merkel, who faces growing pressure to announce a firm deadline for ending her country's use of coal.

Environmental campaigners and poor countries say Merkel should use the event on home turf to signal Germany will phase out the heavily polluting fossil fuel by 2030.

But the timing is difficult for Merkel. After speaking at the climate talks in Bonn she flies back to Berlin for negotiations on forming a new government that would include a pro-business party, the Free Democrats, which opposes a coal deadline.

Also speaking Wednesday are U.N. Secretary-General Antonio Guterres and French President Emmanuel Macron.