Russia's government has summoned the Greek ambassador in Moscow to protest Athen's expulsion of two Russian diplomats, in the latest episode of a diplomatic spat stemming from Macedonia's plans to become a NATO member.

The Russian Foreign Ministry said in a statement that it summoned Ambassador Andreas Friganas on Juy 20 to express a "decisive protest against continued anti-Russian statements by the Greek side."

Greece last week expelled the Russian diplomats from Athens and barred two other Russian envoys from entering the country, charging that they helped fund protests against a settlement of a longstanding name dispute between Greece and Macedonia that has accelerated Skopje's bids to join NATO and the European Union.

Moscow has denied trying to block the settlement by helping to foment protests against it by opposition parties in both Greece and Macedonia, but it has severely criticized the agreement and its goal of facilitating Macedonia's NATO ambitions.

Russia's ambassador to the EU Vladimir Chizhov on July 20 called the agreement legally "dubious," Russian news agency Interfax reported.

Earlier this week, Russian Foreign Ministry spokeswoman Maria Zakharova accused the Greek government of participating in "dirty provocations" against Moscow, and promised a "tit-for-tat" response to the expulsions.

The Greek Foreign Ministry in response denounced what it called "the constant disrespect for Greece" coming from Moscow and said it "must stop."

Macedonia is one of several Western Balkan nations that have ambitions to join NATO and the EU. Russia strongly opposes NATO expansion in the area, which during the Soviet era was under Moscow's orbit of influence.

Based on reporting by AP, Reuters, and Interfax