Mattis said he does not see the need for a stepped-up military posture against Iran, the day after Nikki Haley, the US ambassador to the United Nations, displayed what she called "concert evidence” that a missile fired last month from Yemen at an airport in the Saudi capital Riyadh had been made in Iran.
She called on the international community to join "a united front in resisting this global threat."
When asked if he thought such "evidence” warranted an emboldened or expanded military action against Iran, Mattis told reporters at the Pentagon, "Not militarily, no."
"It's the reason Ambassador Haley was there and not one of our generals," he said. "This is a diplomatically-led effort to expose to the world what Iran is up to."
Mattis accused Iran of "contributing to the deaths of innocent people” in Yemen.
Standing in front of a display of debris from a recovered ballistic missile at a military base in Washington, Haley claimed they were the pieces of a missile fired from Yemen towards Riyadh on November 4.
These weapons "might as well have had 'made in Iran' stickers,” she claimed.
Iranian Foreign Minister Mohammad Javad Zarif once again rejected the allegations, saying Haley’s show was an attempt by Washington "to cover up its presence in the region and measures which can mostly amount to war crimes.”
He said the United States was complicit in Saudi war crimes in Yemen.
The foreign minister was referring to the faulty claims of former US Secretary of State Colin Powell about Iraq having weapons of mass destruction (WMD).
Collin’s speech paved the way for the then administration of President George Bush to begin a war in Iraq.
Powell acknowledged last year that the speech was "a great intelligence failure.”