Prime Minister Scott Morrison has touched down in Sydney after cutting short his Hawaiian holiday, and is expected to meet with fire chiefs on Sunday morning.

Key points: Scott Morrison was criticised for taking leave during the bushfire crisis

Scott Morrison was criticised for taking leave during the bushfire crisis The period of leave was not formally announced and his office told journalists he was not in Hawaii

The period of leave was not formally announced and his office told journalists he was not in Hawaii Earlier in the day, acting PM Michael McCormack conceded more action needed to be taken on climate change

Mr Morrison landed just before 8:00pm (AEDT) on a Hawaiian Airlines flight from Honolulu.

The Prime Minister's return followed days of criticism over his decision to take a family holiday during the bushfire crisis.

The period of leave was not formally announced and the Prime Minister's Office had told journalists he was not in Hawaii.

Mr Morrison announced on Friday morning he would cut short the family vacation, after the deaths of two firefighters in New South Wales.

Mr Morrison returned with multiple fires burning at emergency level across NSW and major fires also burning in Victoria and South Australia.

Earlier on Saturday acting Prime Minister Michael McCormack conceded that the bushfire crisis has increased community concerns about global warming and says he "absolutely" accepts more action is needed to address climate change.

The Nationals leader — who was filling in for Mr Morrison while he was away — has previously criticised people for linking bushfires to climate change.

As several blazes raged at emergency level in New South Wales, Mr McCormack was asked if he accepted that community sentiment and fear of climate change had increased as a result of the unprecedented bushfires and if further action should be taken.

"Yeah I do, absolutely — yeah I do agree entirely," Mr McCormack said.

When asked what more could be done, he said "we'll have those discussions" while adding there has been "a lot of hysteria around climate change".

"The important thing is we put the fires out and wrap our arms around those people who have lost loved ones, the important thing is we fully address these fires as they are occurring," he said.

"Climate change isn't the only factor that has caused these fires.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 1 minute 31 seconds 1 m 31 s Mr McCormack says there will be discussions about climate change but the important thing is to put the fires out.

"There have been dry lightning strikes, there has been self-combusting piles of manure, there has been a lot of arsonists out there causing fires."

Despite agreeing more needed to be done, Mr McCormack took aim at those calling for the shutdown of coal mining, saying the industry "provides almost two-thirds of our energy needs" and contributes $62 billion worth of exports.

"For all those people running around saying we should abandon coal right now, I mean what are they going to do with our electricity and power needs this summer if we stop all our coal fired power stations," he said.

"If we shut them all down today, what on earth are we going to do as far as our energy needs."

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 1 minute 14 seconds 1 m 14 s Emergency warning issued for Gospers Mountain bushfire near Bilpin

Mr McCormack added that he had been receiving briefings on the bushfire situation in New South Wales and South Australia and the Commonwealth was ready to assist if necessary.

He said Mr Morrison was on his way back to Australia and his flight was expected to land later on Saturday.

"Scott Morrison is on his way back to the country and that's a good thing," he said.

"He certainly made it clear that he regrets any offence caused to anyone for him being away."