Russia said Thursday it was expelling five employees of Portugal's embassy in Moscow following the expulsion of Russian diplomats from Portugal as part of joint European action over Ukraine.
The Russian foreign ministry said it summoned Portugal's ambassador in Moscow, Madalena Fischer, to express its "strong protest" against the decision to expel 10 employees of Russia's foreign missions in Portugal.
"It was emphasised that this unfriendly step would have a negative impact on Russian-Portuguese relations," the ministry statement added.
It said that five employees of the Portuguese embassy in Moscow "have been declared persona non grata" and must leave Russian within 14 days.
"The Portuguese government protests against this decision of the Russian authorities, which has no other justification than simple reprisals," Portugal's foreign ministry said in a statement.
It said that unlike the Russian diplomats expelled from Portugal, its diplomats were "carrying out strictly diplomatic activities in full compliance with the Vienna Convention".
Separately, Russia summoned Slovenia's chargé d'affaires and told him his country had 10 days to reduce the staff at its Moscow's embassy by four employees.
The measure came in retaliation to an earlier decision by Slovenia to reduce the staff at Moscow's mission, the foreign ministry said in a separate statement.
The statement said Russia protests "groundless attempts by the Slovenian authorities to blame Russia for war crimes in Ukraine and the provision of military assistance by the Slovenian side to Kyiv's neo-Nazi regime."
A number of European countries have recently expelled Russian diplomats as part of joint action against Moscow's military operation in Ukraine, with Russia responding in kind.
Moscow on Wednesday kicked out more than 80 diplomats from France, Italy and Spain in retaliation for the expulsion of Russian diplomats from their countries.