"I hope that all the positive gains that have been achieved in our relationship will not be damaged by the recent event," Putin told visiting former U.S. President Bill Clinton, according to Reuters.
Earlier, a Russian foreign ministry official called the arrests "groundless."
An 11th suspect, named as Christopher R. Metsos, was arrested in Cyprus today, the Mediterranean island's police said, as he was waiting to board a plane bound for Budapest, Hungary.
"We do not understand the reasons why the U.S. Department of Justice has made a public statement in the spirit of the Cold War," the Moscow official said, according to media reports. The unidentified Russian official said Washington's actions were therefore "highly deplorable."
The arrests came at a time when President Barack Obama had recently proclaimed that ties with Russia were being mended. Just last week, he had a successful meeting with Russian President Dmitry Medvedev.
Foreign Minister Sergei Lavrov had earlier called for the U.S. to give an explanation for the arrests, saying, "The moment when it was done has been chosen with a special finesse."
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Russia's foreign intelligence agency remained quiet on the arrests. "We refuse to comment on these reports," the agency's spokesman, Sergei Ivanov, was quoted as saying by London's Guardian.
The 11 had allegedly been under surveillance since 2000 and were said to have been Russians posing as ordinary citizens but using fake identities. The 10 held in the U.S. have been accused of conspiracy to act as unlawful agents of a foreign government, which carries a five-year prison term if convicted. They are also accused of conspiracy to launder money.
Their mission was to gain intelligence about the U.S. by connecting to think tanks and government officials, The Washington Post today quoted the Justice Department as saying. In this way, the Post reported, they could gather information from policymakers and well-connected insiders without attracting attention.
One official told the paper that the "network" had been "completely compromised." But other officials were quoted as saying that although the suspects had lived in the U.S. for two decades, they appeared to have achieved very little.
A former KGB spy, Oleg Gordievsky, who worked as a double agent for Britain's MI6 agency in the 1980s, told the BBC that he was not surprised by the arrests, but described the type of people sent to the U.S. as "very timid" and relatively harmless.
A different view, however, was offered by Eric O'Neill, a former FBI agent whose work led to the arrest in 2001 of Robert Hanssen, who spied for the Soviet Union for 22 years while serving with the FBI.
He called the current arrests "one of the most severe spy cases in American history" during an interview on ABC's "Good Morning America."
"Just the tenor of the surveillance and the amount of work and effort that was put into catching them shows you how important it was to bring down this spy ring," O'Neill said.




