Washington ? Defense Secretary Donald Rumsfeld said Thursday that anyone demanding deadlines for progress in Iraq should “just back off,” because it is too difficult to predict when Iraqis will resume control of their country.

During an often-combative Pentagon news conference, Rumsfeld said that while benchmarks for security, political and economic progress are valuable, “it’s difficult. We’re looking out into the future. No one can predict the future with absolute certainty.”

He said the goals have no designated deadlines or consequences if they are not met by specific dates.

“You’re looking for some sort of a guillotine to come falling down if some date isn’t met,” Rumsfeld told reporters. “That is not what this is about.”

His comments came less than two weeks before an election for control of Congress in which the Bush administration’s conduct of the war has become a defining issue. They also came two days after a timeline was announced by U.S. officials in Baghdad and underscored strains that have emerged between the two countries.