Prime Minister Scott Morrison has condemned Russia for launching a "brutal invasion" against Ukraine, denouncing the action as a flagrant breach of international law.
"Russia has chosen war," he told reporters in Sydney on Thursday.
"Together with the international community, we are banding together to condemn these outrageous acts in the strongest possible terms."
The condemnation follows Russian President Vladimir Putin's televised declaration of a “military operation” in eastern Ukraine’s Donbas region.
Shelling and explosions have intensified since Mr Putin recognised the two separatist regions of Donetsk and Luhansk as independent and ordered troops into these areas.
Mr Morrison used an evening press conference to add his voice to the West's opposition against Russia's "unprovoked" military escalation in Ukraine.
The prime minister detailed the severe danger now facing Ukrainians as bombs, shelling and bullets are fired and tanks roll across the borders.
"They are suffering a terrible ordeal at the hands of a terrible aggressor," he said.
He also revealed additional sanctions would be imposed against members of Mr Putin's inner circle, declaring there must be a cost to what he describes as their "reprehensible violence".
"We must ensure there is a cost for this violent, unacceptable, and egregious behaviour," he said.
The penalties have now been extended to 25 people, including army commanders, deputy defence ministers and Russian mercenaries.
This follows the government targeting travel bans and financial sanctions against eight members of Russia's national security council on Wednesday.
Sanctions will also be extended to four entities involved in selling military technology and weapons, as well as four further financial institutions.
This builds on other targeted sanctions against specific sectors in Donetsk and Luhansk.
Mr Morrison said further sanctions would be considered as those behind the military action were identified, as part of a joint response with the United States and United Kingdom.
"Sanctions of the order I have outlined matter, they do have an impact - particularly when they are done in concert with other countries," he said.
Australia is not intending to send troops to Ukraine, with the prime minister indicating there has been no formal request for that type of help.
Mr Morrison also said the government would not be expelling the Russian Ambassador to Australia at this stage to maintain a channel of communication.
He also repeated advice urging an estimated 1,400 Australians still located in Ukraine to leave where safe to do so.
"Australians in Ukraine who require consular support should call the 24-hour consular emergency centre," he said.
Russia's military action has prompted widespread condemnation, including from US President Joe Biden, British Prime Minister Boris Johnson and Ukraine’s Foreign Minister Dmytro Kuleba.
Opposition Leader Anthony Albanese earlier on Thursday labelled Mr Putin’s decision to escalate military action a “grave moment for humanity”.
Mr Albanese said all Australians stood with the people of Ukraine “united in condemnation of Russia’s shameful act of aggression”.
“This attack is wholly unprovoked and without justification. Russia alone is the aggressor, and Russia alone bears responsibility for the bloodshed and suffering that will follow,” he said in a statement.
“Australia must stand united with our allies, in holding Russia to account.”
Opposition Leader Anthony Albanese is seen during a press conference on the Gold Coast. Source: AAP / DARREN ENGLAND/AAPIMAGE
Victorian Premier Daniel Andrews has also responded to the military intervention, which he said would “cause harm and untold suffering to thousands, if not millions of people.”
In a statement, he said public buildings in Melbourne’s central business district would be lit up in blue and yellow in support of the people of Ukraine and their families.
The head of Ukraine’s embassy in Australia, Volodymyr Shalkivskyi, also said Mr Putin’s declaration marked “the beginning of a new wave of aggression against Ukraine”.
“The goal of the Russian offensive military operation is to destroy the Ukrainian state, seize Ukrainian territory by force and establish occupation control,” he said.
“This is an act of war, an attack on sovereignty and territorial integrity of Ukraine, a gross violation of the UN Statute and the fundamental norms and principles of international law.”
Russian forces have fired missiles at several cities in Ukraine and landed troops on its coast since Mr Putin's declaration, according to officials and media.
Tens of thousands of Russian troops are stationed near Ukraine's borders, and the West had said for days that an attack was imminent.
