The United States Tuesday confirmed that a staff member of the US embassy in Moscow was "briefly detained and was released", dpa reported.
State Department spokesman Patrick Ventrell declined to give any more details about the officer, who Russia claims was a US diplomat working as a CIA operative. Ventrell identified the person only as a "staff member" of the embassy, not as a foreign service officer or diplomat.
Ventrell dismissed the suggestion that the incident would derail efforts by Moscow and Washington to bring together an international conference on Syria.
"I'm not sure I'd read too much into one incident one way or another," Ventrell said, noting that US Secretary of State John Kerry would meet later Tuesday with his Russian counterpart Sergei Lavrov in Sweden.