Russia is in "no rush" to retaliate against Australia and other countries who kicked out Russian spies and diplomats.
Two spies now have four days to leave Australia, after they were kicked out in a show of solidarity with the UK over the poisoning of former double agent Sergei Skripal and his daughter Yulia in Salisbury.
Russia's Deputy Foreign Minister Sergei Ryabkov said Moscow is in "no rush" to retaliate, and told the RIA Novosti state news agency that Russia is "thoughtfully and thoroughly" considering its response.
President Vladimir Putin's spokesman Dmitry Peskov told reporters a response would come soon and it will be "timely and will suit the interests of Russia".
The Russian ambassador to Australia Grigory Logvinov used a media conference to deny Russia was behind the Skripal poisoning and said his diplomats weren't spies.
But Prime Minister Malcolm Turnbull wasn't buying it.
"I think he'll be applying for an Oscar, don't you think? He didn't persuade anybody," Mr Turnbull told reporters on Thursday.
"It was a very lengthy performance, and all of the histrionics aside, the fact of the matter is this: chemical weapons were used in an attempt to murder a person ... on British soil."
More than 20 nations have announced the expulsion of more than 150 Russian diplomats in the dispute, including 60 from the United States.
Britain expelled 23 and Russia retaliated with the same number, but it has not responded to the other moves.
Foreign Minister Julie Bishop on Wednesday hauled Mr Logvinov in for a "please explain" meeting, where he said Russia wants an investigation into the nerve agent attack.
But Ms Bishop said Russia had not declared its Novichok chemical weapons, which were used in the Skripal attempted assassination.
Australia believes Russia has breached the convention by its failure to declare the Novichok program.