Several prominent figures, including the heads of the two most populated countries in the world, are in doubt to attend the 31 October - 12 Nobember UN COP26 climate summit in Glasgow in person.
Here is the latest on the status of delegates:
Out/still to confirm
- The leader of the world's most populous country, China's Xi Jinping, will reportedly not be there in person, given that he has not left China since the Covid-19 pandemic began. He is likely to make an appearance by video.
- Indian Prime Minister Narendra Modi is yet to decide whether he will attend, a foreign ministry source told Reuters. Between them, India and China make up a third of the world's population.
- Pope Francis is not now expected to attend. A Vatican source said there was a possibility that the pope would address the conference by video or that Cardinal Secretary of State Pietro Parolin would read a message on his behalf.
- Iran's President Ebraham Raisi will not attend COP26 after reports in the British press that local politicians were calling for a criminal investigation if he set foot in Scotland.
- Brazilian President Jair Bolsonaro and Vice President Hamilton Mourao, who has sometimes been the point man for environment, are not going.
- The Kremlin has not yet announced if Russian President Vladimir Putin will attend.
- Mexican President Andres Manuel Lopez Obrador is not going and Mexico may not send anyone because of pandemic restrictions and costs.
- South African President Cyril Ramaphosa is not going because of local elections on 1 November.
- New Japanese Prime Minister Fumio Kishida has said he is still considering how he will participate, including the possibility of taking part online.
- US President Joe Biden, along with climate envoy John Kerry and domestic climate adviser and former EPA Administrator Gina McCarthy. The White House says 10 other cabinet officials will also be present.
- Queen Elizabeth, Prince Charles and Prince William along with Camilla, Duchess of Cornwall, and Kate, Duchess of Cambridge.
- Israeli Prime Minister Naftali Bennett.
- Australian Prime Minister Scott Morrison confirmed on Friday he will go. While many global nations have pledged to achieve net zero emissions by 2050, Australia has refused to strengthen its targets.
- President Recep Tayyip Erdogan will attend after Turkey's parliament ratified the Paris climate agreement last month.
- French President Emmanuel Macron.
- Canadian Prime Minister Justin Trudeau is expected to announce that he will attend closer to the start date, according to a government source.
- Italian Prime Minister Mario Draghi.
- Colombian President Ivan Duque.
- Swedish Prime Minister Stefan Lofven.
- Swiss President Guy Parmelin.
- South Korean President Moon Jae-in is expected to attend, but the presidency has not made an official announcement yet.
- Democratic Republic of Congo's President Felix Tshisekedi, current chair of the African Union.
- Nigerian President Muhammadu Buhari.
- Ghana's President Nana Akufo-Addo.
- Argentinian President Alberto Fernandez.