Russia has expelled 59 diplomats from 23 countries, including Australia, and said it reserved the right to take action against four other nations in a worsening stand-off with the West over the poisoning of a former Russian spy and his daughter in Britain.
Prime Minister Malcolm Turnbull has called the expulsion of two Australian diplomats from Russia "disappointing, although not unexpected".
He has defended the federal government's decision to order two Russian diplomats working as undeclared intelligence officers to leave the country, calling it and similar decisions taken by 28 other nations "an unprecedented demonstration of global solidarity with the United Kingdom".
In a statement, Mr Turnbull says there is no justification for Moscow to take such action.
He has demanded the Russian government explain how the military-grade nerve agent was used in the UK, and clarify why its chemical weapons program has not been declared in line with legal obligations.
Russia said it was responding to what it called the baseless demands for scores of its own diplomats to leave a slew of mostly Western countries that have joined London and Washington in censuring Moscow over the poisoning of Sergei Skripal and his daughter Yulia.
On Wednesday Ms Bishop announced two Russian spies had been given six days to leave Australia, in a show of solidarity with the UK over the poisoning of former double agent Sergei Skripal and his daughter Yulia in Salisbury.
Labor supports Turnbull government decision
Labor leader Bill Shorten supported the government's decision, calling it an appropriate and proportionate response.
"The Russian Government must understand there are real consequences for engaging in attacks on foreign soil and refusing to tell the truth about them," he said in a joint statement with Labor senator Penny Wong on Saturday.
"We have to act in the way that we believe is in Australia's national interest, and on this occasion that was sending a strong signal that we reject Russia's action and we stand with our friends and allies."
Australia's ambassador to Russia Peter Tesch was among the diplomats summoned to the Russian foreign ministry on Friday to be told of the expulsions.
The diplomatic mission in Moscow has 10 staff.
Biggest explusion of jection of diplomats since the Cold War
A day earlier, Moscow ordered the expulsion of 60 US diplomats and the closing of the US consulate in St Petersburg, Russia's second city, in retaliation for the biggest ejection of diplomats since the Cold War.
Preparations appeared to be under way on Friday to close the St Petersburg mission down, with a removals truck making repeated journeys to and from the consulate, which took delivery of a large pizza order for its staff.
Russia on Friday summoned senior envoys from most of the other countries, including Australian ambassador Peter Tesch, that have expelled Russian diplomats and told them it was expelling a commensurate number of theirs.
Russia has already retaliated in kind against Britain for ejecting 23 diplomats over the first known use of a military-grade nerve agent on European soil since World War Two. British ambassador Laurie Bristow was summoned again on Friday.
The Russian foreign ministry said Bristow had been told London had just one month to cut its diplomatic contingent in Russia to the same size as the Russian mission in Britain.
A spokeswoman for the British Foreign Office did not say how many British diplomats would be affected, but said Russia's response was regrettable and Moscow was in flagrant breach of international law over the killing of the former spy.
The poisoning, in southern England, has united much of the West in taking action against what it regards as the hostile policies of President Vladimir Putin. This includes the US under President Donald Trump, who Putin had hoped would improve ties.
Russia rejects Britain's accusation it stood behind the attack and has cast the allegations as part of an elaborate Western plot to sabotage East-West relations and isolate Moscow.
The hospital where she is being treated said on Thursday that Yulia Skripal was getting better after spending three weeks in a critical condition due to the nerve toxin attack. Her father remains in a critical but stable condition.
The BBC, citing sources, reported on Friday that Yulia was "conscious and talking".
During the course of Friday, the Russian foreign ministry summoned senior embassy officials from Australia, Albania, France, Germany, Italy, Poland, the Netherlands, Croatia, Ukraine, Denmark, Ireland, Spain, Estonia, Latvia, Lithuania, Macedonia, Moldova, Romania, Finland, Norway, Sweden, Canada and the Czech Republic.
All were seen arriving in their official cars at the foreign ministry's gothic building in Moscow.
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"They (the diplomats) were handed protest notes and told that in response to the unwarranted demands of the relevant states on expelling Russian diplomats ... that the Russian side declares the corresponding number of staff working in those countries' embassies in the Russian Federation persona non grata," the ministry said in a statement.
The US State Department said after Russia announced the expulsions on Thursday evening that it reserved the right to respond further, saying the list of diplomats designated for expulsion by Russia showed Moscow was not interested in diplomacy.
Kremlin spokesman Dmitry Peskov, in a conference call with reporters on Friday, disagreed with that assessment, saying that Putin still favoured mending ties with other countries, including with the United States.
