"We are mourning the three American firefighters who died in the Large Air Tanker crash in the Snowy Monaro area today," Ms Payne said.

"Our hearts go out to their loved ones. They were helping Australia, far from their own homes, an embodiment of the deep friendship between our two countries."

Ms Payne said she had conveyed Australia’s condolences to the United States Ambassador, Arthur B. Culvahouse - who earlier released his own statement.

"Thank you to these three, and to all the brave firefighters from Australia and around the world. Your service and contribution are extraordinary. We are ever grateful," Ms Payne said.