UN leader Ban Ki-moon on Tuesday condemned "shrill" talk of war between Israel and Iran which he said would be devastating.
Without mentioning the two rivals by name, Ban told the start of the UN General Assembly that he rejects "threats of potential military action by one state against another.
"Any such attacks would be devastating. The shrill war talk of recent weeks has been alarming," he told the 193-nation assembly where the showdown over Iran's nuclear program is one of the dominant themes.
Iran's President Mahmoud Ahmadinejad, who is in New York, has shrugged off talk of an Israeli attack on his country's nuclear facilities. But US President Barack Obama was to warn that the United States would "do what we must" to stop Iran getting a nuclear weapon.
Iran has denied western accusations that it seeks a nuclear bomb.