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."
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.