Karzai, however, said any decision to let US troops cross Afghanistan's border should be taken collectively by Pakistan, Afghanistan and the United States.

"I would fully back President (Barack) Obama in attacking Al Qaida wherever they're found. If they're found in Afghanistan, I would fully back him in doing that. If they're found in Pakistan, I would fully back him in that," Karzai said in an interview to CNN.

"On the question of crossing troops from Afghanistan into Pakistan in pursuit of Al Qaida personnel, or for destruction of Al Qaida hideouts, or training grounds, or sanctuaries, this is something that the government of Afghanistan, and Pakistan, and the US must work together and agree upon together, and then implement," Karzai said in the interview that would be aired on Sunday.

Obama had said during his campaign that if actionable intelligence was found he would attack Al Qaeda hideouts in Pakistan, even without the approval of Islamabad.

Karzai said Obama is a great inspiration to the world. "I consider him a remarkably great person but I hope our friends in the West understand," he said.

Obama in the past few months has been critical of Karzai's administration. At a press conference early this week, Obama had said the Afghan Government seems to be detached with what is happening in its surrounding.

"Surely he understands Afghanistan. He's a very intelligent person, as well. Given the right reporting by his administration, given the right figures by the administration, he'll figure out very quickly as to how things are in Afghanistan," Karzai said.

At the same time, the Afghan leader observed that people in his part of the world also have sensitivities and morality and are concerned over civilian casualties in US-led attacks on militant targets.