Ukrainian President Volodymyr Zelenskyy has told Prime Minister Scott Morrison in a phone call he deeply appreciates Australia's military and humanitarian assistance after his country was invaded by Russian forces.
Mr Zelenskyy tweeted on Saturday night that he had updated Mr Morrison on the course of the war "as well as risks to people and the environment due to the threat to Ukrainian nuclear and chemical facilities".
Foreign Minister Marise Payne had earlier over shelling and a fire at a building near the Zaporizhzhia nuclear plant on Friday.
The fire was extinguished and international nuclear experts later said the facility was safe, with no radiation spikes reported.
Mr Zelenskyy said he deeply appreciated the military and humanitarian support from Australia, according to an official readout of the call, while Mr Morrison told him Australia stood with Ukraine against Russia's aggression and unprovoked assault.
The prime minister also praised Ukraine's incredible courage and condemned Russia's actions on behalf of all Australians.
Australia is also supporting resolutions in the United Nations and backing International Criminal Court action in support of Ukraine.
The government has told superannuation funds it has a "strong expectation" they would review their investment portfolios and divest any holdings of Russian assets.
Appearing on the ABC's Insiders program on Sunday, Defence Minister Peter Dutton said missiles and ammunition supplied by Australia had arrived in Ukraine.
Mr Dutton also spoke of the "inevitability" of the conflict, adding that Australia would continue to provide support.
"What is very clear to us is that President Putin has a view of erasing history and of conquering those countries around him and bringing back a re-unified USSR. That is very clearly his intent," he told the ABC's Insiders program.
"That is the view out of Ukraine, the view out of the intelligence analysts and that is what concerns NATO and the world as well. Dos it stop at the Ukraine or does it provide them with a greater foothold in Europe and a launching pad then into another country?
"Ukrainians have put up a magnificent resistance so far, but there is a sense of inevitability when you look at the strength and sheer numbers and also the propensity for Putin to use chemical weapons or other weapons with would be used in a residential area that would have an outcome we just couldn't imagine."
Mr Dutton said Australia "will continue to provide support when we think it is in Ukraine's best interests and our national interest to be involved in that".
Liberal senator James Paterson, who chairs the parliamentary joint committee and intelligence and security, is currently on an official trip to the US where he was briefed in Washington and the United Nations.
He says there is some cautious optimism at the remarkable united response that the global community has presented Russia and President Putin.
"There has been incredible resolve about enacting the highest possible costs on Putin and his cronies to deter and and deflate him from this course of action and hopefully get them to rethink the course of action they have embarked upon," Senator Paterson told Sky News' Sunday Agenda program.
Federal Labor's defence spokesman Brendan O'Connor also told the program the Australian government has done the right thing in joining the condemnation and providing lethal and non-lethal aid to Ukraine.
"Our hopes of course that through such action we'll see an end to this violence and this conflict, and until we see anything like that, we need to ratchet up the pressure," Mr O'Connor said.
"If the government has any other options in so far as increased sanctions, whether it is targeting the oligarchs or is providing lethal aid through NATO, Labor supports that."
