Yesterday, the US State Department said the Islamic Republic "continued to sponsor global terror" attacks last year and supplied arms to the Syrian regime even though it was engaged in talks to rein in its nuclear programme.
But Iranian foreign ministry spokeswoman Marzieh Afkham said those accusations were "worthless."
"For three decades, Iran has been the great victim of terrorism and considers international cooperation to combat terrorism a priority," she said, without elaborating.
US counterterrorism envoy Tina Kaidanow, unveiling the 2014 Country Reports on Terrorism, said "Iran continued to sponsor terrorist groups around the world," adding that Washington remained very concerned by the activities of the Iranian Revolutionary Guard "and its proxies."