Sen. Hillary Rodham Clinton, who clashed with defense officials this summer over demands for a briefing on troop-withdrawal plans for Iraq, has signed on to a bill mandating the Pentagon report those plans to Congress. The bill by Sen. Ken Salazar, Colorado Democrat, would require Defense Secretary Robert M. Gates to report within 60 days and every 90 days thereafter on the development of plans for the U.S. mission and reduced troop strength in Iraq, including potential timetables for force reductions. "The roots of the many problems facing our men and women serving in Iraq were planted by the failure of this administration to develop sound, realistic plans," said Mrs. Clinton, New York Democrat, who is seeking the nomination for president. "We cannot afford to repeat the same mistake when our forces redeploy." The bill, which is identical to legislation the House passed Tuesday 377-46, does not set a deadline for a pullout from Iraq. The Senate bill is co-sponsored by Republicans Lamar Alexander of Tennessee, Susan Collins of Maine, Elizabeth Dole of North Carolina and George V. Voinovich of Ohio. Democratic Sens. Mark Pryor of Arkansas and Jim Webb of Virginia also endorsed the legislation. Republican leaders have said the bill is inconsequential, merely highlighting ongoing Pentagon planning for a gradual drawdown of troops. The bill could provide Senate Democrats, frustrated by repeated failed bids to force a pullout, with a gesture to the party's antiwar base. Senate Majority Leader Harry Reid, Nevada Democrat, who dismissed similar bills as too weak earlier this year, declined to comment yesterday on the Salazar bill. "We must all work together to find a new way forward in Iraq and this bill is an important first step," Mr. Salazar said. "This is a substantive and bipartisan effort to work together to bring a responsible and timely redeployment of our troops. The men and women that are fighting this war in our name deserve no less." Supporters say the bill ensures congressional oversight of military strategy in Iraq and provides a bipartisan approach to the war issue. Mrs. Clinton got a briefing on troop-withdrawal plans in August after a dust-up with Defense Undersecretary Eric S. Edelman, who said her request for a briefing, which was publicized by her campaign, "reinforces enemy propaganda." She characterized the remark, in a letter to her office, as "impugning the patriotism of any of us who raise serious questions."