Washington: In his talks with Afghanistan President Hamid Karzai, US President Barack Obama has expressed his "sorrow" over recent civilian deaths in NATO air strikes in the war-torn country.

Besides it, Obama discussed with him a series of issues including drawdown of troops and the progress in the war against terrorism in the aftermath of the killing of al Qaeda leader Osama bin Laden.

“Obama expressed his sorrow over tragic civilian casualties, most recently in Helmand province," White House Press Secretary Jay Carney told reporters at his daily news conference.

Video conference between the two leaders lasted for about one hour, during which they also discussed regional dynamics, their shared commitment to Afghan-led reconciliation and progress on forging an enduring US–Afghan strategic partnership, and transition to Afghan leadership for security.

Both leaders noted that the Taliban are responsible for civilian losses, and agreed that every loss of civilian life is a tragedy and undermines our mission that focuses on protecting the population.

“The two leaders agreed to maintain close consultations ," he said, adding the two Presidents discussed the process of transition to an Afghan lead.

“They agreed to continue consultations and President Obama will certainly, be in close touch with President Karzai as we finalize the pace and scope of the reduction in US troops that will begin in July," he said. "There was not a discussion of specific numbers," he said when asked about the drawdown of the number of troops.

“It remains the case, the President has not made a decision yet about the pace and scope. He's obviously going to be having discussions with his team in the coming days and weeks about that matter and will make his decision soon, as he said the other day," Carney said.

 “We have broken Taliban's momentum. We are training Afghan forces, with the goal of turning over security lead to the Afghan forces between the drawdown that begins in July 2011 and 2014.

Civilian assistance is important but it represents a small proportion of the overall cost of our mission in Afghanistan. But it is an essential component of our critical national security strategy in Afghanistan," he said.

“If the goal here is to make transition of more and more responsibility to the Afghans and the Afghan security forces, it’s important that the civilian assistance part of this be effective so that it builds capacity that allows us to do just that," he said.