"This is not a pleasant place to be," firefighters said, urging the public to take caution and heed evacuation advice.
"Thank you, Firies," said the message to those battling Australia's record-breaking wildfires.
The singer volunteered at Melbourne's Foodbank to package food hampers for those affected by the country's worst fire crisis.
The conservative leader defended his government's climate policy, rejecting pleas to downsize the nation's massive coal industry.