Here's what we know at the moment:
"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.
The Creewah Road fire has been downgraded, leaving the Clyde Mountain and Badja Forest Road fires as the only two still at emergency level.
Weather conditions are expected to improve overnight.
The US Ambassador to Australia Arthur Culvahouse has released this statement in response to the tragedy.
This week on Please Explain Chris Zappone talks to Peter Hannam and Laura Chung from the Sydney Morning Herald about how devastating these bushfires have been on Australia's flora and fauna.
He said he had received field reports of properties being damaged or destroyed, but no confirmed number at the moment.
"I have run out of adjectives to describe how tragic such an event is, given the enormity of the fire season so far," Mr Fitzsimmons said.
The Commissioner said that the addition of large air tankers had given the RFS capability and capacity that they "simply haven't had before," while mourning the loss of three American firefighters.
"To lose three remarkable individuals that are so experienced and so professional in their expertise when it comes to firefighting and fire management is a tragedy to say the least."
Federal and state NSW National Party MPs have jointly declared hazard reduction to be one of the "vital factors" to help address the bushfire crisis, calling for "innovative solutions" such as grazing to reduce fuel loads.
The NSW Nationals outlined this position in a letter circulated to its membership, after MPs met with the party's Nationals Central Executive in Sydney on Tuesday to discuss the impact of the fires on their communities.
The threat of mass fish kills is emerging across the Murray-Darling Basin as low river flows and the influx of soil and ash from bushfires reduce water quality.
Matt Hansen (right), president of the Inland Waterways group, with his sons, Jack (left) and Cooper, near dead fish pulled from the Macquarie and Bell rivers near Dubbo in recent days.Credit: Matt Hansen
In recent days, fish deaths have been reported in the Macquarie River near Dubbo and the Macleay River east of the Dividing Range in NSW, while a "wall of mud and ash" is moving down the Upper Murray.
The Kings Highway has reopened in both directions between North Batemans Bay and Nelligen, the Transport Management Centre said on Thursday evening.
The Princes Highway remains closed in three sections - between Coila and Bodalla, between Tilba Tilba and Cobargo, as well as between Narrabarba and the Victorian border.
Motorists are still advised to avoid these areas.
Many other roads remain closed in the south of New South Wales.
Premier Gladys Berejiklian announced that as a mark of respect for the three US firefighters who died in a crash today, that flags would fly at half-mast around the state tomorrow.