Washington, May 15 (IANS/RIA Novosti): US officials were tight-lipped over the arrest of US diplomat Ryan Fogle in Moscow who has been accused of trying to recruit an agent for the CIA.

"We can confirm that an officer at the US embassy in Moscow was detained briefly and was released. We've ... no further comment," State Department spokesperson Patrick Ventrell said.

Fogle, a third secretary in the political department at the US embassy, was detained May 13 night as he allegedly attempted to recruit an officer from one of Russia's special services, said Russia's Federal Security Service (FSB).

Russia quickly declared Fogle persona non grata and called for him to be deported.

Asked if the arrested man was still in Russia and if he was a spy, Ventrell said: "I really have no further information for you."

The spokesperson played down speculation that the diplomat's arrest could put a damper on recent joint efforts by the US and Russia to organise an international conference on Syria.

"We have a very broad and deep relationship with the Russians across a whole host of issues and we will continue to work on our diplomacy with them directly," he said.

According to FSB, the diplomat was found to be in possession of "special technical devices, written instructions for the Russian citizen being recruited, a large sum of cash and means of changing his appearance".

Fogle purportedly offered the Russian officer up to $1 million a year for his cooperation, according to a letter he was carrying that was released by FSB.

Fogle was taken to FSB and, after "necessary procedures" were completed, handed over to US embassy officials.

Relations between Moscow and Washington have been strained during US ambassador Michael McFaul's tenure, with bones of contention including US criticism of Russia's human rights record.

The FSB released photographs of the diplomat's detention, including pictures of the man identified as Fogle, his IDs, two floppy wigs, three pairs of glasses, a map of Moscow and a folding knife.