Defense Secretary Robert Gates is disputing the characterization of a memo he wrote in January suggesting the U.S. needed to advance a long-term plan for dealing with Iran's nuclear program.

Gates said Sunday allies and foes should have no doubt the U.S. is prepared to act "across a broad range of contingencies" in support of its interests with Iran. He said the memo identified steps to be taken in defense planning after Washington decided to increase pressure against Iran's nuclear ambitions.

Government sources told The New York Times the memo prompted a scramble to come up with new options, including military ones. But Gates says he was merely laying out an orderly and timely decision-making process.