Iran on Friday refused to confirm or deny a claim by a US official that Russian missiles targeting rebels in Syria crashed in its territory this week.

"We don't confirm" this information, foreign ministry spokeswoman Afkham Marzieh said when asked about the claim.

The US official, who spoke on condition of anonymity, had said the missiles crashed in Iran on Wednesday, but did not provide details about where they might have come down or whether they caused any damage.