Kabul: The "strategic defeat" of al-Qaeda is "within reach", Leon Panetta said on Saturday, as he arrived on a surprise first visit to Afghanistan in his new role as United States Defense Secretary.

Former CIA chief Panetta, who took office on July 1 to replace Robert Gates, arrived in Kabul for a trip to include talks with President Hamid Karzai over the transition of some NATO-held areas to Afghan control starting mid-July.

US President Barack Obama has announced that 10,000 US forces will leave Afghanistan this year and another 23,000 by the end of September in 2012, ahead of a full withdrawal of foreign forces in 2014.

Before his arrival, Panetta told travelling media that since the May night raid by US forces in Pakistan that killed Osama Bin Laden, 10-20 key al-Qaeda targets had been identified between Pakistan, Yemen, Somalia and North Africa.

"If we can go after them, I think we really can strategically defeat Al-Qaeda," said Panetta, who leads the Pentagon after two years as head of the CIA.

"Obviously we made an important start with that with getting rid of bin Laden. I was convinced in my prior capacity and I'm convinced in this capacity that we're within reach of strategically defeating al-Qaeda."

Agencies