"The Secretary General and President Lula of Brazil will convene a small but representative group of heads of states and government for a virtual, closed door meeting to discuss strengthening global efforts to tackle the climate crisis and to accelerate the just energy transition," Guterres spokesman Stephane Dujarric told reporters.

He said the aim of the meeting was to strengthen climate action dialogue ahead of COP30 in the Amazonian city of Belem later this year that will mark a decade since the signing of the Paris Agreement.

The closed-door format would promote a free and frank exchange, Dujarric said, without elaborating on which leaders would be taking part.

The world's nations agreed during the landmark Paris climate accord of 2015 to try to hold end-of-century warming to 1.5C above pre-industrial levels.

Many signatories that were expected to submit new climate action strategies by February this year have yet to do so.

The upcoming COP30 summit follows the second US withdrawal from the landmark pact and other global efforts to address climate.

There are concerns meanwhile that climate change is being crowded out of the global agenda by national security and economic pressures.