NATO has expelled two Russian diplomats in retaliation for a spy scandal earlier this year in which an Estonian diplomat was jailed for passing secrets to Moscow.
Russia called the move an attempt to set back recent efforts to improve relations between Washington and Moscow.
The diplomats were attached to Russia's mission at NATO headquarters. Citing alliance officials, Reuters reports that one of the expelled Russians was Vasily Chizhov, the son of Vladimir Chizhov, Moscow's ambassador to the European Union.
Dmitry Rogozin, Russia's ambassador to NATO, told Russian television that he was summoned to a meeting with NATO Secretary-General Jaap de Hoop Scheffer, where he was told that Chizhov and senior counselor Viktor Korchakov were being expelled in response to Russian espionage:
"I consider this decision by NATO as pure provocation aimed at disrupting all of our recent agreements with regard to the resumption of the Russia-NATO Council and our future plans, including a ministerial meeting of the Russia-NATO Council," Rogozin said.
Russia has recently sought to improve relations with NATO, and the United States in particular, after years of acrimony.
The United States has called for a "reset" in its relations with Moscow and U.S. President Barack Obama and his Russian counterpart Dmitry Medvedev met in London in April where the two agreed to pursue a new strategic arms pact.
Rogozin said the two diplomats had "no link" to any spy scandal and speculated that the expulsions were an attempt to derail Russia's rapprochement with the West.
"None of the reasons given by [NATO's] secretary-general make any sense, because our diplomats are doing only their professional, diplomatic work," Rogozin said.
"It is my belief that someone in the West is very unhappy with the way relations between Russia and certain Western European countries are developing and does not want a 'reset' in our relations with the United States and European countries to take place."
Russia's Foreign Ministry also released a statement calling the expulsions a "crude provocation" based "on an absolutely trumped-up pretext without any clear explanation."
Reuters quoted an unidentified NATO official as saying that the two were expelled over the case of Herman Simm, an Estonian Defense Ministry employee sentenced to more than 12 years in prison in February for passing classified information to Russian intelligence.
Simm worked at the Defense Ministry from 1995 to 2006 and had access to top secret documents related to NATO, which Estonia joined in 2004.
NATO ordered the diplomats out on April 29, the same day the alliance resumed formal talks with Russia at ambassadorial level. Those contacts had been suspended for eight months due to Russia's five-day war with Georgia in August 2008.
On April 30, NATO also criticized Russia for an agreement giving Moscow direct control over the de-facto borders of Georgia's breakaway South Ossetia and Abkhazia regions.
Russia is vowing to retaliate for the expulsions. It is still unclear whether the move will affect cooperation between Moscow and NATO over issues like piracy and the war in Afghanistan.
Russian Foreign Minister Sergei Lavrov is scheduled to meet with NATO foreign ministers in May.
with agency reports