In a year marked by progress in Iraq, US Defense Secretary Robert Gates acknowledged two bits of unfinished business in his first 12 months on the job: He has yet to close the Guantanamo Bay prison or find Osama bin Laden. Gates held out hope that if security gains hold, US troop levels in Iraq can drop through next year. But with a nod to the increased attacks in parts of Afghanistan, he did not rule out a small uptick in US troops there. While Gates would not put a specific number on Iraq troop levels, he agreed a consistent reduction over the next 12 months would leave 10 brigades there - or roughly 100,000 troops - soon after American voters go to the polls for the 2008 presidential elections. "My hope has been that the circumstances on the ground will continue to improve in a way that would - when General (David) Petraeus and the chiefs and Central Command do their analysis in March - allow a continuation of the drawdowns at roughly the same pace as the first half of the year," he said Friday during a Pentagon news conference. Gates acknowledged he still has not found a way to overcome the legal obstacles and shut down the Guantanamo Bay, Cuba, detention facility where 285 suspected terrorists are being held - some for as many as six years. "I think that the principal obstacle has been resolving a lot of the legal issues associated with closing Guantanamo and what you do with the prisoners when they come back," he said. "So, I would say that the honest answer is that because of some of these legal concerns ... there has not been much progress in this respect." At the same time, US military forces have not found bin Laden, the man responsible for the Sept. 11, 2001, attacks. "We are continuing the hunt," Gates said, adding that progress will be marked by the day when "the president goes out in front and says that we have either captured or killed him." Gates acknowledged that the US is looking at adding a small number of forces in Afghanistan, where the US already carries the largest share of the load with about 26,000 troops. The US has been pressing allies to increase their commitment there. Gates said that he is still looking for creative ways for them to do that - including meeting commanders needs for 3,500 more trainers, another 3,000 combat troops, and some helicopters. Asked if the US will fill any of those troop requirements, he said the Pentagon "will be looking at the requirements ourselves. And we will be talking with our allies." A former CIA director, Gates took over the Pentagon last December after the embattled Donald Rumsfeld stepped down. Since then he has seen both victories and defeats. Overall, however, Iraq dominated his year - with four trips to the war front, an overhaul of his commanders, a shift in strategy and a battery of hearings and reviews. "It was a year that began with a surge of troops in Iraq and has ended with a sharp decline in violence," Gates said. "The war is far from over. And we must protect and build on the gains earned with the blood of our military, our allies and our Iraqi partners." Gates was cautiously optimistic about further troop reductions. But he said he regretted putting a specific number on that projection in September, when he expressed the hope that forces could drop to 100,000, by the end of 2008 if conditions in Iraq improved. "We obviously want to sustain the gains that we have already made," he said, adding that the capacity of Iraqi forces to bear more of the security burden and the ability of the Iraqi government to run the country are keys to how quickly US forces can leave. There are 158,000 US troops in Iraq. Plans call for reducing the 20 combat brigades to 15 by next summer. Five more could come out in the second half of the year, he said, if security gains continue. One combat brigade that left Iraq this month became the first to not be replaced. Asked about the possibility of political reforms in Iraq, Gates said the country's leaders "are committed to getting it done. We'll see if they get it done." The progress in Afghanistan has been mixed, Gates said, noting that violence increased as the coalition forces launched more aggressive attacks against the insurgents. Al-Qaida also has stepped up its activities. He said he was told Friday morning that there has been a 40 percent drop in cross-border attacks in eastern Afghanistan over the last six months. Gates also signaled a small, if temporary, victory on Friday, saying that because Congress recently passed legislation providing $70 billion for combat operations, there will be no layoff notices sent out during the holiday season. That possibility had loomed until Congress passed the spending bill. Still, he warned that paying for the wars in Iraq in Afghanistan in fits and starts undermines military planning and risks the gains made by American troops. And noting that the funding is less than half that requested by the president, Gates said the layoffs and cutbacks may resurface in a few months.