'Killing of civilians outrageous, but no rush for exit'

United States President Barack Obama on Tuesday said that the killing of innocent Afghan civilians is outrageous and unacceptable, but asserted he would continue with the strategy to responsibly drawdown troops from Afghanistan.

"The killing of innocent civilians is outrageous, and it's unacceptable. It's not who we are as a country, and it does not represent our military," Obama told reporters at the White House in the aftermath of killing of 16 Afghans by an American soldier.

"For that reason, I've directed the Pentagon to make sure that we spare no effort in conducting a full investigation.

I can assure the American people and the Afghan people that we will follow the facts wherever they lead us, and we will make sure that anybody who was involved is held fully accountable with the full force of the law," Obama said.

On Sunday Obama had spoken to his Afghan counterpart Hamid Karzai.

"What I've made to President Karzai when I spoke to him is that the United States takes this as seriously as if it was our own citizens and our own children who were murdered. We're heartbroken over the loss of innocent life," he said.

Obama said on Monday that he met his commander in Afghanistan, Gen John Allen, and US Ambassador to Afghanistan, Ryan Croker.

"I have extraordinary confidence in them and in the many Americans who are serving in Afghanistan and who have made extraordinary sacrifices to be there," he said.

Obama said he would be meeting British Prime Minister David Cameroon to consult about the way forward as they prepare for the NATO summit in Chicago later this spring.

"So make no mistake: We have a strategy that will allow us to responsibly wind down this war. We're steadily transitioning to the Afghans, who are moving into the lead. And that's going to allow us to bring our troops home," he said.

He said the US was scheduled to remove 23,000 troops by the end of this summer, following the 10,000 that it withdrew last year.

"And meanwhile we will continue the work of devastating Al Qaeda's leadership and denying them a safe haven," Obama said.

Acknowledging that there is no question that they face a difficult challenge in Afghanistan, Obama exuded confidence that they can continue the work of meeting our objectives, protecting the country and responsibly bringing this war to a close.

Obama has made it clear that international forces will not "rush for the exits" in Afghanistan.

"It's important for us to make sure that we get out in a responsible way, so that we don't end up having to go back in but what we don't want to do is to do it in a way that is just a rush for the exits," Obama told reporters.

On Sunday, an American Army staff sergeant went on a shooting spree and killed 16 civilians, including nine children and three women, in southern Afghanistan.

The shooting marked another low in the ties of the two countries after a wave of deadly protests over burning of Quran.