After shooting rampage in Afghanistan, no shift in U.S. strategy

The White House on Monday reaffirmed plans for U.S. troops to leave Afghanistan no later than 2014 as it denied any shift in strategy in America's longest war after the slaughter of 16 Afghan civilians by a U.S. soldier.

"As tragic as these events are, the strategy is focused on disrupting, dismantling and defeating al-Qaida, stabilizing Afghanistan so that Afghan security forces can take responsibility for the security of their country," spokesman Jay Carney told reporters. "Our strategic objectives have not changed, and they will not change."

His comments came after a U.S. soldier, identified in press reports as an Army staff sergeant, walked off his base in southern Afghanistan early Sunday and killed 16 Afghans, mostly children. The massacre immediately inflamed already deteriorating ties and raised fresh questions about the NATO-led campaign.

"Incidents like this do not make it any easier," said Carney. "This is a challenging time, there's no question."

Carney also noted that the pace and scope of the troop withdrawal will be a central subject of the NATO summit in Chicago in May.

"The pace of that withdrawal will depend on a variety of factors that will certainly be discussed in Chicago, at the NATO meeting, and will be discussed running up to Chicago and in the aftermath of Chicago," he said.

But Carney emphasized that Obama is committed to not "staying any longer than we have to" and insisted that the U.S. strategy will not change "in reaction to a single event."

And Carney said Obama "remains very concerned" about the security of Americans—both civilians and military—serving in Afghanistan.

Obama is to host British Prime Minister David Cameron at the White House on Tuesday in his first meeting with a key ally since Sunday's incident, and the two leaders are sure to discuss the tragedy.

"We are clearly very concerned that this terrible incident does not lead to a cycle of retaliation," British envoy to the United States Peter Westmacott told journalists at a press briefing in Washington on Monday. "We hope that [Afghans] understand that this unacceptable incident was created by one person who seems to have lost his head."

Westmacott said that international coalition discussions are continuing with the Afghans on the reconciliation process as well as on a post-2014 strategic partnership agreement. "Before long, we hope there will be the conclusion of the strategic partnership," he said. "My prime minister is certainly determined to stick to the strategy he laid out." However, he "may want to review" those issues with allies going into the NATO summit in Chicago in May "so we are clear about where we are."

After the United States, Britain is the second-largest contributor to NATO's 130,000-strong, U.S.-led International Security Assistance Force (ISAF) in Afghanistan.

French President Nicolas Sarkozy has said NATO's withdrawal should be moved up to 2013, and a new ABC News/Washington Post poll found U.S. public sentiment against the war at near-record highs.

A narrow majority, 54 percent, of respondents said U.S. troops should withdraw on time whether or not Afghan forces are self-sufficient.

And the survey—which was conducted on Saturday, before the reported killing spree—found that 60 percent of Americans say the war has not been worth fighting. That's just 4 points shy of the record 64 percent who said the same thing one year ago.