Members of the Royal Family have said their "thoughts and prayers" are with Australians affected by the massive bushfires.
The Queen and the Duke of Edinburgh sent a message of condolence expressing thanks to emergency services.
The Duke and Duchess of Cambridge said they were "shocked and deeply saddened" by the loss of life.
And the Duke and Duchess of Sussex urged support for fundraisers for those affected by the environmental crisis.
The Queen said she was "deeply saddened" to hear about the fires which have ravaged Australia since September, killing at least 23 people, destroying at least 1,200 homes and scorching millions of hectares of land.
Her message addressed to the Governor General of Australia, Governor of New South Wales, Governor of Queensland, the Governor of Victoria and to all Australians was also posted on the Royal Family's Twitter account.
The Queen said: "My thanks go out to the emergency services, and those who put their own lives in danger to help communities in need.
"Prince Philip and I send our thoughts and prayers to all Australians at this difficult time."
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Our thoughts and prayers are with those across Australia who are continuing to face the devastating fires that have been raging for months. From areas we are personally connected to such as the communities and people we visited in New South Wales in 2018, to the fires in California and parts of Africa, we are struck by the increasingly overlapping presence of these environmental disasters, including of course the destruction of the Amazon which continues. This global environmental crisis has now been described as Ecocide. It’s easy to feel helpless, but there’s always a way to help. To find out how you can lend your support, please see the links below to help as we have. https://www.rfs.nsw.gov.au/about-us/fundraising (@nswrfs) https://fundraise.redcross.org.au/drr (@redcrossau) Photo © @nswrfs / @dale_appleton / Jay Elai
The Duke and Duchess of Cambridge and the Duke and Duchess of Sussex posted messages on their Instagram accounts.
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We continue to be shocked and deeply saddened to hear about the wild fires that are destroying homes, livelihoods and wildlife across much of Australia. Our thoughts and prayers are with all the people and communities who are affected by this devastating event. We send our deepest condolences to the families and friends of those who have tragically lost their lives, and the brave firemen who continue to risk their own lives to save the lives of others. The Duke and Duchess of Cambridge Image courtesy of @nytimes
Prince William and Catherine said: "We send our deepest condolences to the families and friends of those who have tragically lost their lives, and the brave firemen who continue to risk their own lives to save the lives of others."
Prince Harry and Meghan said they were "struck by the increasingly overlapping presence" of "environmental disasters" across the world.