No timeframe for US shift in Afghanistan: Panetta Pentagon chief Leon Panetta said Friday it was too early to say when US forces might pull back from combat operations in Afghanistan after the US Marine Corps commander suggested the move might come within a year for his forces. Panetta, speaking during a visit to Canada, said the United States and its allies were working to eventually hand over combat duties to Afghan forces but there was no deadline for the transfer. "We're moving in the right direction," he told reporters at a joint news conference with Canada's Defence Minister Peter MacKay. "We're trying to get the Afghan army and the Afghan police to assume more of the responsibilities with regards to combat operations. But this is going to take a transition period and I would not assign a particular date or timeframe for that," he said. The Pentagon chief was asked about comments from the commandant of the US Marine Corps, General James Amos, who said in an interview that he expected Marines in the southern Helmand province to shift in coming months from fighting insurgents to training and advising Afghan forces. "Im pretty confident... that over the next 12 months that we can transition from what you would call classic counter-insurgency operations to... training and advising" Afghan forces, Amos said in an interview with The Hill newspaper. The roughly 20,000 Marines deployed in Helmand are "working really hard" to bolster local governments and security forces there, the general said. "Im very confident that the Afghans can take care of this on their own," Amos was quoted as saying. The general's comments follow signals from the Pentagon that commanders are looking at a change in strategy that would mean taking a supporting role as soon as next year, which could possibly pave the way for a faster drawdown of US troops. Such a change would allow more time for coalition troops to build up the Afghan forces and provide help when things go wrong, officials say. Under current plans endorsed by NATO, the US-led force is due to hand over security for the whole country by the end of 2014, though US officials have hinted at a possible smaller, follow-on force. With 97,000 US troops and 45,000 allied soldiers, the NATO-led force has concentrated on rolling back Taliban insurgents in towns and cities while training Afghan army and police. US commanders have tended to push for more time for combat operations and for delaying withdrawals of troops as much as possible, but some inside and outside the Pentagon are arguing for handing over to Afghan forces sooner while more NATO boots are still on the ground. MacKay suggested the NATO-led coalition was hoping to push the transition effort forward at a more rapid pace. "There is a desire in fact, and I would suggest it's happening, to meet and exceed timelines. Whether we'll get there is going to depend on this very focused effort to train Afghan security forces," he told reporters. MacKay and Panetta were speaking at the start of the Halifax International Security Forum, which gathers defense ministers from around the world.