Iran has described the US Navy's rescue of 13 Iranian fishermen held by Somali pirates as a "humanitarian gesture".Foreign Minister Ali Akbar Salehi said his country had also rescued foreign sailors from pirates on occasion.
But he said such acts did not affect overall relations between countries.
The Americans say they freed the Iranian fishermen in the Arabian Sea after more than a month in captivity, and provided fuel and food for them to return home.
The rescue was carried out by forces assigned to the John C Stennis aircraft carrier group, which recently left the Gulf to assist US military operations in Afghanistan.
According to a New York Times reporter who boarded the captured Al Molai with the US forces, the Iranian fishermen expressed great gratitude for their rescue, with one saying: "It is like you were sent by God."
But Iran's Fars news agency expressed suspicion about the operation, saying it was "like a Hollywood film" which "seems to have been pre-organised".
Earlier in the week, the US rejected an Iranian warning to keep its forces out of Gulf waters after Western powers unveiled new sanctions on Iran over its nuclear programme.