Iran denied reports from Washington that it played a part in failed missile attacks on US naval vessels off Yemen, saying on Thursday that the claims were "false and paranoid".
"The vague and contradictory remarks by American officials these past days are false, paranoid and inappropriate," foreign ministry spokesman Bahram Ghasemi told the official IRNA news agency.
Washington has accused Iran-backed Shiite rebels in Yemen of firing surface-to-surface missiles at the destroyer USS Mason on at least two occasions in recent weeks.
A top US general, Joseph Votel, told a Washington think tank on Wednesday that "some of the technology that we've seen there are things that are associated with" Iran, though he acknowledged "it's not totally exclusive to them."
Ghasemi responded by saying that it "would be preferable for the American army -- which has an undeniable role in the atrocities committed against the Yemeni people by its direct or indirect support for the coalition forces -- to prevent further atrocities."
Washington provides intelligence and logistics support to a Saudi-led coalition that has been fighting the Yemeni rebels since March last year.
The United Nations says that since the intervention started, the conflict has killed almost 6,900 people, mo re than half of them civilians.
Washington responded to the missile fire targeting the Mason with cruise missile strikes that destroyed three radar sites controlled by the rebels on October 13.