"The Secretary-General expects to focus the attention of these leaders on key issues that require their engagement in the climate change negotiations, in particular concerning mitigation and finance," said UN spokeswoman Michele Montas.

The UN chief will be in Trinidad on November 26 and 27 as international leaders converge on the Caribbean island for the Commonwealth Heads of Government Meeting.

World leaders will gather in Copenhagen from December 6 for a summit to negotiate emission targets and complete a successor agreement to the Kyoto protocol, which expires in 2012.

"The Secretary-General hopes to boost momentum for an ambitious outcome in Copenhagen that will advance international action on climate change," Montas said.