WASHINGTON (AFP) - US Defence Secretary Robert Gates on Sunday touted military success in Iraq, and stressed he did not expect changes to US troop drawdown plans there. Asked if the United States will have achieved victory when it withdraws from Iraq, Gates said, "we have had a significant success (on) the military side," while acknowledging, "The political side is still a work in progress in Iraq. "Frankly, I think before you start using terms like 'won' or 'lost' or 'victory' or 'defeat,' those are the kinds of things that I think historians have to judge," he told NBC television. Asked about the projections for the troop levels of an interim force, which angered many Obama supporters eager for a full withdrawal, Gates said: "I don't think it was a concession (to commanders). "I think that there was a lot of analysis of the risks that were involved. I think that if the commanders had had complete say in this matter that they would've preferred that the combat mission not end until the end of 2010," he said. So "it was really a dialogue between the commanders in the field, the joint chiefs here myself, the chairman and the president, in terms of how you mitigate risk and how you structure this going forward," Gates said. "Having a somewhat larger residual, or transition, force, mitigates the risk of having the combat units go out sooner," he explained. "Mozul is a problem. The Arab/Kurd tensions are a problem. The need to get an oil law is a problem. So, there are problems," he said. "We have the concerns associated with a national election at the end of this year as one of the reasons why (General US military commander in Iraq General Ray) Odierno wanted to keep those troops there as long as possible. Or a significant number of troops." While "there has been real progress on the political side ... there is clearly unfinished business in that arena, as well." The US defense chief also said he did not see the drawdown schedule as likely to be changed. "I would characterize the likelihood of significant adjustments to this plan as fairly remote," said Gates. The timeline Obama laid out Friday will unfurl at a slightly slower pace than his promise to remove all US combat troops from Iraq within 16 months from his inauguration in January. The transitional force will take on a new mission of training, equipping and advising Iraqi security forces, to protect US civilian personnel in Iraq, and to conduct targeted counter-terrorism operations on its own and in conjunction with the Iraqi forces, Obama said. Speaking privately, officials earlier refused to definitively rule out changes to the status of forces agreement, agreed with Iraq by the former Bush administration, that could entail US troops remaining beyond 2011.