Having Russia at the G20 table after President Vladimir Putin has been accused of war crimes would be "a step too far," Scott Morrison says.
The prime minister says Australia shares the United States' assessment that war crimes have been committed in Ukraine.
"We know Vladimir Putin's form when it comes to taking the lives of innocent civilians. Russia has form," he said.
Mr Morrison said Australia had been raising concerns about Mr Putin's attendance at the G20 summit in Bali in November.
"The idea of sitting around a table with Vladimir Putin, who the United States are already in the position of calling out war crimes in Ukraine, for me is a step too far," he told reporters in Melbourne on Thursday.
He appeared to rule out an Australian boycott of the G20, saying it would be disappointing if serious issues the forum deals with weren't addressed.
"We want to make sure that the G20 for Indonesia is successful and we want to work closely with Indonesia as our partner," he said.
"We want it to focus particularly on the challenges of our region in the Indo-Pacific ... (but) we need to have people in the room that aren't invading other countries."
Foreign Minister Marise Payne said Australia was working with other G20 nations to determine whether Mr Putin should be allowed to attend this year's summit.
"These are very sensitive issues ... not just in relation to the G20, but multiple international and multilateral organisations where this is a matter that we have to address," she said.
"We work closely with other members of the G20, particularly Indonesia, on this."
Opposition Leader Anthony Albanese said Australia needed to act in unison with international partners and allies.
"We should act as one (with) those countries around the world who find the actions of people abhorrent, who find it a breach of international law, a breach of human rights," he said.
"The ongoing tragedy with the bombing of innocent civilians in Ukraine is quite rightly condemned by Australia but also condemned by all of us who have a concern for decency and human rights."
Expelling Russia's ambassador to Australia also remains an option, one month on from the invasion of Ukraine, the foreign minister said.
Ahead of a major NATO summit in the wake of the invasion, Senator Payne said there was still a united front of other nations against Russia.
"There are a range of approaches globally, but the importance of the unity in that coalition ... is a very strong and unified coalition against Russia's illegal war," she told ABC Radio on Thursday.
"We never stopped seeking a diplomatic resolution ... and that is essential."
While Senator Payne said Australia had engaged with Russia's ambassador and its diplomats since the invasion began last month, the government was still considering whether to expel the ambassador.
"I'm not going to speculate on Australia's approach. I have said (expelling the ambassador) remains a live option on the table for this government," she said.
"At the same time, it is potentially useful to have direct lines of communication with, in this case, the Russian government ... we're working with partners we always do to determine the best approaches."
Senator Payne said the sanctions placed on Russia by western nations were a warning to authoritarian regimes of the cost of unilateral action.
US President Joe Biden is heading to Europe to take part in the emergency NATO summit, along with a meeting of the G7 and European Council.
Mr Biden will try to rally support in Brussels to impose new sanctions on Russia and deal with the unfolding humanitarian crisis.
The US and Europe are also in discussions about how they would respond if Russia were to use chemical or nuclear weapons.
with AP
