It has been confirmed by defense Secretary Robert Gates that he cautioned the White House about U. S. policy on Iran's nuclear program but denied his advice had been "wake-up call."

The New York Times, citing government officials, reported in its Sunday editions that Gates issued the warning in January in a memo to Gen. James L. Jones, President Barack Obama's national security adviser.

It was further reported that in the memo, Gates expressed concern about the lack of an effective strategy if Iran were to become a "virtual" nuclear weapons state by assembling all the parts needed for a nuclear weapon but not putting it together, enabling the country to stay on as a signatory of the Nuclear Nonproliferation Treaty.

The Times also reported that in response to the report, Gates issued a statement saying his intention in writing the memo was "to contribute to an orderly and timely decision-making process."

The statement said, "With the administration's pivot to a pressure track on Iran earlier this year, the memo identified next steps in our defense planning process where further interagency discussion and policy decisions would be needed in the months and weeks ahead."

Gates said, "The memo was not intended as a 'wake-up call' or received as such by the president's national security team. Rather, it presented a number of questions and proposals intended to contribute to an orderly and timely decision-making process."

They described only parts of the memo about strategy and policy, not sections about secret operations against Iran or dealing with its Persian Gulf allies, the officials who spoke to the Times, said.

The newspaper further said that Gates spokesman Geoff Morrell initially declined to comment on specifics in the memo.

"The secretary believes the president and his national security team have spent an extraordinary amount of time and effort considering and preparing for the full range of contingencies with respect to Iran," Morrell said in a statement on Saturday. (With Inputs from Agencies)