The top U.S. military officer described the situation in Afghanistan as «serious and deteriorating,» but refused to say today whether defeating a resilient enemy would require more than the 68,000 American troops already committed, according to AP. Adm. Mike Mullen also expressed concern about eroding public support as the U.S. and NATO enter their ninth year of combat and reconstruction operations. The comments from the chairman of the Joint Chiefs of Staff underscore the challenges that the U.S. and its allies face against a resurgent Taliban and al-Qaida fighters who use safe havens in neighboring Pakistan to hide and launch attacks. In broadcast interviews, Mullen and U.S. Ambassador Karl Eikenberry said that last week's presidential election in Afghanistan was historic, given the threats of intimidation voters faced as they headed to polling stations. It could be several weeks before it's known whether incumbent Hamid Karzai or one of his challengers won. «We're not sure exactly what the level of voter turnout was,» said Eikenberry, a retired three-star Army general. «Taliban intimidation, especially in southern Afghanistan, certainly limited those numbers.» President Barack Obama's strategy for defeating the Taliban and al-Qaida is a work in progress as more U.S. troops are put in place, Mullen said. The situation in Afghanistan needs to be reversed in the next 12 month to 18 months, he said. But Mullen wouldn't say whether more American forces troops would be needed. A large number of civilian experts is also required to help bring stability to Afghanistan's government and develop the economy, he said. «I think it is serious and it is deteriorating, and I've said that over the last couple of years, that the Taliban insurgency has gotten better, more sophisticated,» Mullen said. Three years ago, the U.S. had about 20,000 forces in the country. Today, it has triple that, on the way to 68,000 by year's end when all the extra 17,000 troops that Obama announced in March are to be in place. An additional 4,000 troops are arriving to help train Afghan forces. «I recognize that we've been there over eight years,» he said. «But this is the first time we've really resourced a strategy on both the civilian and military sides. So in certain ways, we're starting anew.» «We're just getting the pieces in place from the president's new strategy on the ground now,» he said. «I don't see this a mission of endless drift. I think we know what to do.» The Obama administration is awaiting an assessment about the situation from the top U.S. commander in Afghanistan, Army Gen. Stanley McChrystal. That report is expected in about two weeks and will lead to decisions about whether more troops are necessary. «His guidance from me and from the secretary of defense was to go out, assess where you are, and then tell us what you need,» Mullen said. «And we'll get to that point. And I want to, I guess, assure you or reassure you that he hasn't asked for any additional troops up until this point in time.» Just over 50 percent of respondents to a Washington Post-ABC News poll released this past week said the war in Afghanistan is not worth fighting. Mullen, a Vietnam veteran, said he's aware that public support for the war is critical. «Certainly the numbers are of concern,» he said. But, he added, «this is the war we're in.» Arizona Sen. John McCain, the top Republican on the Senate Armed Services Committee, said he wants the military leadership in Afghanistan to use the same aggressive approach that Gen. David Petraeus used successfully in Iraq. McChrystal should say exactly how many troops he needs in Afghanistan, let the Congress debate it and Obama would make the ultimate decision, McCain said. Troops in Afghanistan should «clear and hold» an environment for people so that economic and political progress can be made, he said. McCain said he worries McChrystal will be pressured to ask for lower troop totals than he needs. «I don't think it's necessarily from the president,» he said. «I think it's from the people around him and others and that I think don't want to see a significant increase in our troops' presence there.» On the question of what it will take to turn the tide in Afghanistan, McCain echoed Mullen's projection: «I think within a year to 18 months you could start to see progress.» McCain acknowledged that public opinion on Afghanistan is slipping. But he said that opinion could be reversed. «I think you need to see a reversal of these very alarming and disturbing trends on attacks, casualties, areas of the country that the Taliban has increased control of.»