With no heavy rainfall expected, the 640,000-hectare (1.58 million-hectare) fire that was created overnight when two fires merged into the Snowy Mountains region near Tumbarumba, near the Victorian border, is expected to burn for weeks, officials said.
Kangaroo Island off South Australia is on notice as a massive bushfire is described as "virtually unstoppable".
New South Wales Premier Gladys Berejiklian said there were more than 130 fires burning in the state, with just over 50 not yet under control.
A fearless firefighter died while on duty on Saturday in Australia's state of Victoria, increasing the toll from this season's disastrous bushfires to 28 death losses as the power deploys mental health services to help and assist those in concerned areas.
For more on the Australian fires, pick up this week's issue of PEOPLE, on newsstands Friday.
"This makes heat waves and fires more likely", she said on Twitter.
As firefighters from around the world continue to assist in fighting the fires in Australia, members of the Huron Manistee National Forest - based out of Cadillac, Michigan - are among those helping.
People across Australia are calling on the government to implement stronger climate measures.
Mr Morrison, who plans to take a proposal for a bushfires royal commission to cabinet in coming weeks, has also faced insults and anger from locals as he visited bushfire-hit areas.
Cooler weather conditions have brought a temporary respite for numerous country's burning areas over the weekend, but a firefighter died on duty in Victoria, where new flames sparked.
"We don't want job-destroying, economy-destroying, economy-wrecking targets and goals, which won't change the fact that there have been bushfires or anything like that in Australia", Morrison told Sydney radio 2GB on Friday.
Previous year was Australia's hottest and driest on record.
He tweeted a story from the conservative Australian that misleadingly said 180 people had been arrested on arson charges, though they were from bushfire-related charges and only 24 were charged with deliberately lighting fires.
The fires have claimed at least 26 lives and destroyed more than 2,000 homes across Australia.
But he said any change would be done without "shutting down traditional industries" or with new taxes.
Across New South Wales, almost 140 fires were still burning by Saturday afternoon, 59 of them not contained, but none at emergency level.
Westpac estimated total wildfire losses to date at about A$5 billion, higher than the 2009 wildfires in Victoria but smaller than the Queensland floods in 2010/11.
Poor and very poor air quality conditions due to the bushfires are forecast statewide, with smoke and haze in the east, northeast and central Victoria.
The move comes in response to Australia's gesture in 2018, when the country had sent their own teams of firefighters to California to help fight a series of blazes that had erupted across the state.
The fires have emitted 400 megatonnes of carbon dioxide and produced harmful pollutants, the European Union's Copernicus monitoring program said.
Also on Sunday, news came that another firefighter had been killed.