NEW YORK - Vice President Joe Biden has argued an expanded US presence in Afghanistan might undermine a more critical objective - helping Pakistan achieve stability - as the Obama administration debates options to deal with the situation there amid falling public support, according to a leading American newspaper. Citing government officials, The New York Times said senior Obama advisers are divided on whether to send more troops to war-torn Afghanistan for combat duty. One official said a healthy debate was underway on priorities in Afghanistan. On his part, Biden has argued that a sizable increase in resources for Afghanistan invariably means less for Pakistan, a concern he said was born out of his frustration as a senator during the Bush administration pushing for more aid to Islamabad. In some ways, he has told colleagues, Pakistan is more important than Afghanistan because extremism is on the rise there, al-Qaeda has operating room and the government of Pakistan, a nuclear-armed nation, remains vulnerable, according to The Times. Richard Holbrooke, the special representative to the region, is also concerned about Pakistan, the report said, but thinks sending more troops to Afghanistan is essential. General Stanley McChrystal, the top commander of US troops in Afghanistan, submitted a classified report this week, which is now in President Obamas hands. Other American officials said they worried that General McChrystal simply did not have enough forces to turn around Afghanistan. Defence Secretary Robert Gates has voiced concern that putting so many troops in Afghanistan would make the United States look like an occupier, but during a news conference on Thursday he sounded more supportive of the prospect. There is a unanimity of opinion about what our objective is, and the objective is to disable and destroy Al Qaeda and remove that threat to our national security, David Axelrod, the presidents senior adviser, was quoted as saying. Obviously, there are a variety of opinions about how best to achieve that objective, and its valuable and important to hear those views. Although General McChrystal included no specific force proposals in his review, officials expect him to send a separate request in the coming weeks. Citing military strategists, the Times said Gen. McChrystal might offer three options. The smallest proposed reinforcement, from 10,000 to 15,000 troops, would be described as the high-risk option. A medium-risk option would involve sending about 25,000 more troops, and a low-risk option would call for sending about 45,000 troops. Geoff Morrell, the Pentagon press secretary, cautioned that talk about troop levels was speculation. Anyone who tells you that they know how many troops the commander is going to ask for and the options he may or may not present doesnt know what hes talking about, because that has not been determined yet, Morrell said. He said that Gates had not made up his mind about what he would recommend to President Barack Obama. Secretary of State Hillary Rodham Clinton has been vocal in favour of more troops, and while some officials said she had not shown her hand during the current deliberations, they expected her to be an advocate for a more robust force, the Times said. The emerging debate follows the delivery Monday of a new strategic assessment by Gen McChrystal that Gates has now forwarded to Obama. The Times said Defence Secretary Gates could be the key adviser on this decision, and some military analysts predicted that he might recommend what Pentagon officials call the Goldilocks option - the medium-risk one in the middle. Because he was first appointed by President George W. Bush, Gates could provide political cover for Obama should the president reject the biggest possible buildup. At a news conference with Admiral Mike Mullen, the chairman of the Joint Chiefs of Staff, Gates said Thursday that his concerns about the American footprint had been mitigated by General McChrystal, who has indicated that the size of the force is less important than what it does. Where foreign forces have had a large footprint and failed, in no small part it has been because the Afghans concluded they were there for their own imperial interests and not there for the interests of the Afghan people, Gates said. But he said that General McChrystals emphasis on reducing civilian casualties and interacting more with Afghans has given us a greater margin of error in that respect. Obama has already ordered 21,000 additional troops to Afghanistan this year for a total American force of 68,000, on top of 40,000 NATO troops. Clinton and Holbrooke pushed for those reinforcements, while Biden resisted. It is true that Hillary was very forceful; I had some disagreement in degree with her, Biden later told USA Today. The president ended up landing on a spot that was where she was. Other American officials said they worried that General McChrystal simply did not have enough forces to turn around Afghanistan. Mr Holbrooke just returned from Afghanistan, where he heard from military officers who said they needed more help to execute General McChrystals strategy of protecting the population from the Taliban, rather than just hunting militants. As the presidents senior uniformed adviser, Admiral Mullen has said he worries about the impact of a buildup on the nations already stretched armed forces. In July, Gates announced a temporary increase of 22,000 troops in the size of the Army. Mediating the debate will be Gen James Jones, the national security adviser. My job is to make sure the process works the way the president wants and everybody is at the table, he said. I try to be open-minded and not prejudice anything. He said he would ensure that dissidents got to voice their views to Obama. He encourages vigorous debate, General Jones said. The thing not to do in a meeting with the president is to sit on your hands and hope you dont get called on, because thats a guarantee that youre going to get called on.