Speaking to the network from Paris, Burns said NATO forces had intercepted arms shipments from Tehran in Afghanistan.

"There's irrefutable evidence the Iranians are now doing this and it's a pattern of activity," Burns said. "Iran is operating against the last (U.N.) Security Council Resolution 1747, passed on March 24, which said that Iran must not transfer arms outside of Iran, and here it is doing it in Lebanon, in Gaza, in Afghanistan and in Iraq, so Iran is in outright violation of its Security Council commitments."

Burns told CNN there was no chance the shipments were coming from rebel groups in Iran.

"It's certainly coming from the government of Iran. It's coming from the Iranian Revolutionary Guard corps command, which is a basic unit of the Iranian government," he said.

NATO officials in Afghanistan have said some Iranian-made AK-47s, plastic explosives, mortars and one Explosively Formed Penetrator bomb that can pierce coalition armor had been intercepted.

There was no immediate response from Tehran, CNN said.