The U.S. secretary of state made the comments in Jordan during the World Economic Forum, Voice of America reported.
Powell said it is "absolutely wrong" to believe the U.S. would mount any kind of aggressive action against Iran, VOA said.
He did, however, say the U.S. supports Iranian protests against the Islamic clerical regime. Powell said Iranians should enjoy freedom of speech. But he denied Washington was actively backing the protests.
Earlier in the day, Russian President Vladimir Putin said although his government has some serious questions about Iran's nuclear program, it considers the country an ally.
Putin vowed not to let international concerns over Iran's nuclear capabilities to get in the way of his country's commercial interests in Iran.