King Charles III speaks with Kenyans from multiple sectors as he attends a reception at the British High Commissioner's Residence in Nairobi on Wednesday. Reuters

The British monarch, 74, who has campaigned on environmental issues for most of his life, will attend the start of the United Nations climate meeting on Dec.1 in Dubai on behalf of the government and following an invite from President His Highness Sheikh Mohamed Bin Zayed Al Nahyan.

It will be the third time that the British monarch, 74, who has campaigned on environmental issues for more than 50 years, will deliver the opening speech, having done so at Glasgow's COP26 and at COP21 in Paris.

On the eve of the summit, Charles king will attend a reception to launch the inaugural COP28 Business and Philanthropy Climate Forum, which is running alongside the UN event, the palace said.

"While in the UAE, the king will take the opportunity to have meetings with regional leaders, ahead of COP28," the statement added.

King Charles III gestures as Queen Camilla looks on during a visit to Sheldrick Wildlife Trust Elephant Orphanage in Nairobi on. AFP

Countries hope to strike a deal on the increase in capacity at the global climate negotiations which will run from Nov.30 to Dec.12 with a focus on the gaps in the implementation of the 2015 Paris Agreement that established the 1.5°C ceiling.

In a speech on Wednesday at the United Nations office in Nairobi, where he is taking part in a state visit, Charles called for unity among nations before COP28.

"Left unchecked, global warming, biodiversity loss and climate change are challenges which threaten us all and can only be met by the whole of society working together in the spirit of action, partnership and commitment," he said.