"Those of you who have tragically lost your properties, your houses, everything – to me it is, and to both of us, not to be believed possible. And I know how many houses have been lost.
"But above all, we wanted to say how much we've been thinking of all those remarkable, courageous, determined firefighters who have done so much and worked ceaselessly to exhaustion. And we feel so deeply for the families of those who have been lost and have lost their lives in the course of carrying out their remarkable duties, as only they can do.
"We also think of all the Australian wildlife that is destroyed in these appalling infernos, let alone everything else.
"I know, we both know, just how incredibly special and resilient the Australian people are, so I know at the end of the day, despite all this horror, you will find a way to face it all and win through.
"All I can say is that we are thinking of you, we are praying for you in the most determined way … I'm very proud to know you all."
His speech ended with a link to the Red Cross website, urging people to donate.
Meanwhile, Prince William and Kate Middleton are reportedly planning to tour bushfire-ravaged Australian towns this year.
It was reported last month that talks have been under way between the federal government and Kensington Palace for weeks, and that a formal invitation from Prime Minister Scott Morrison is expected imminently.