Two Russian spies have left Australia

Two Russian spies have left the country after being given their marching orders from the Australian government in a show of solidarity over the poisoning of a former spy in the United Kingdom.

Foreign Minister Julie Bishop last week gave two "undeclared intelligence officers" seven days to depart.

Ms Bishop told AAP the Russian Embassy staff had complied with the deadline and left the country.

Australia expelled the pair after the UK, US and European allies lined up to boot out alleged Russian spies following the nerve agent attack on former double agent Sergei Skripal and his daughter Yulia in Salisbury.

Britain has expelled 23 Russians, the US 60 and France and Germany four.

London blames Moscow for the attack but Russia denies involvement.

The Kremlin has since retaliated, announcing it will expel two Australian diplomats as part of its "symmetrical" response to the various expulsions.

Australia's two diplomats are expected home by Friday.

"Our first priority is to look after our staff by assisting those who will be returning to Australia and we ask that their privacy be respected," Ms Bishop and Prime Minister Malcolm Turnbull said in a joint statement on the weekend.

Australia's Department of Foreign Affairs and Trade has updated its travel advice for Russia, warning Australian travellers to brace for possible harassment or anti-western sentiment, due to heightened political tensions.