US 'within reach of strategic defeat of al-Qaeda'
New US Defence Secretary Leon Panetta has said the US is "within reach of strategically defeating al-Qaeda".
Mr Panetta said that following the killing of Osama Bin Laden, key leaders in Pakistan, Yemen and elsewhere had been identified and would be targeted.
He offered the upbeat assessment during his first visit to Afghanistan since taking over at the Pentagon last week.
Earlier, a member of Afghanistan's intelligence service shot dead two US soldiers in the Panjshir valley.
The National Directorate of Security (NDS) officer, a bodyguard for its deputy director, was killed when another US soldier returned fire.
The soldiers were accompanying a Provincial Reconstruction Team when they were stopped by the officer. It is believed there was an argument when they asked him to remove his vehicle from a bridge.
He had been on holiday in the north-eastern area at the time.
Afghan soldiers and police have turned on Nato-led troops in the past, but it is thought to be the first such incident involving an NDS official.
Several hours after the incident, Mr Panetta arrived in the Afghan capital, Kabul, on a previously unannounced visit.
He plans to meet US troops and their commanders, as well as President Hamid Karzai and other Afghan government officials.
They will discuss President Barack Obama's plan to withdraw 10,000 US troops this year and another 23,000 by the end of September 2012.
Speaking to journalists, Mr Panetta revealed that US analysts had determined that following the death of Bin Laden in May, killing or capturing "around 10 to 20 key leaders" of al-Qaeda and its offshoots would cripple the network.
"We're within reach of strategically defeating al-Qaeda," he said. "The key is that, having gotten Bin Laden, we've now identified some of the key leadership within al-Qaeda, both in Pakistan as well as in Yemen and other areas."
"If we can be successful at going after them, I think we can really undermine their ability to do any kind of planning, to be able to conduct any kind of attack," he added. "That's why I think it's within reach."
Mr Panetta declined to name all the key leaders, but said they included Bin Laden's successor, Ayman al-Zawahiri, and the radical American Muslim cleric of Yemeni descent, Anwar al-Awlaki, who US officials claim is a senior leader of al-Qaeda in the Arabian Peninsula (AQAP).
Zawahiri was believed to be hiding in the Federally Administered Tribal Areas of western Pakistan, he added, while Awlaki is thought to be living in a remote, mountainous part of central Yemen under the protection of his tribe.
Mr Panetta also said he believed the replacement of several key US officials in Afghanistan, including Ambassador Karl Eikenberry, would reset the deteriorating relationship with President Karzai.
"Hopefully, it can be the beginning of a much better relationship than what we've had over the last few years," he said.
He said the biggest challenge for the US in the country remained training Afghan forces so they can take over security responsibility by 2014.
"We've made good progress on that, but I think there's a lot more work to do of being able to transition responsibility to them," he added.