Obama Vows 'Full Force' of Law in Afghan Shooting

U.S. President Barack Obama Tuesday sought to calm outrage over a shooting massacre by a U.S. soldier in Afghanistan, saying he took the tragedy as seriously as if Americans had been slaughtered.

Obama promised that the culprit who killed 16 civilians, mostly women and children in a methodical house-to-house killing spree, would face the "full force" of U.S. law -- wherever the investigation led.

The somber U.S. commander-in-chief said he had assured Afghan President Hamid Karzai 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," Obama said. "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 said he had directed the Pentagon to spare no effort in a full investigation into why a gun toting U.S. army sergeant and veteran of three tours of Iraq, apparently left his base and mounted a lone orgy of murder.

"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," he said.

His comments, in an appearance in incongruent calm of the White House Rose Garden, came hours after Taliban insurgents threatened revenge against "sick-minded American savages ... for every single martyr" of the massacre.

Obama's decision to again address the incident in a public setting, appeared to underline deep U.S. concern about the possibility of reprisals against American forces and a further unraveling of U.S. prospects in Afghanistan.

It also came amid growing public debate about the state of U.S. war strategy which is now being thrust into the heat of a U.S. election as Obama campaigns for a second term, and tries to run on strong national security credentials.

The president said that he met the U.S. ambassador to Kabul, Ryan Crocker, and Afghan mission commander General John Allen on Monday to discuss his strategy for a responsible withdrawal, fight to crush al-Qaida and to effort to provide Afghans with the means of securing their own security.

"There's no question that we face a difficult challenge in Afghanistan, but I'm confident that we can continue the work of meeting our objectives, protecting our country and responsibly bringing this war to a close," Obama said.

Earlier, the U.S. embassy in Kabul urged its citizens to take extra precautions, warning against "a risk of anti-American feelings and protests in coming days especially in eastern and southern provinces."

Defense Secretary Leon Panetta meanwhile warned on Monday that the soldier suspected of the massacre could face the death penalty if convicted.

Officials have however dismissed calls by the Afghan parliament for the soldier, a veteran of three combat tours of Iraq, to face a public trial in Kabul.

Sunday's massacre poses an acute test of the tense U.S.-Afghan alliance, as the two countries pursue difficult talks on securing a strategic pact to govern their partnership once foreign combat troops leave Afghanistan in 2014.

Obama noted that there were already plans to withdraw 23,000 more U.S. troops from Afghanistan by the end of this summer, following the 10,000 surge forces drawn down last year.

But behind the scenes, there is a growing impression that Obama, and some of his Western allies, facing declining public support for the war, are keen to promote a quicker drawdown than military brass might want.

The New York Times reported the White House could reduce the U.S. footprint in Afghanistan by an additional 20,000 troops by next year.

The pace of the drawdown, and plans to transfer more responsibilities to Afghan authorities next year will dominate the NATO summit in Chicago in May.

Obama however warned Monday against a "rush for the exits" in Afghanistan, as he tries to balance making a responsible departure from Afghanistan after a decade-long war, with a U.S. desire to prevent a return to the chaos exploited by groups like al-Qaida.