Mr. Obama spent about two minutes at the beginning of a longer statement about new U.S. actions with key partners on China trade practices to stress his determination to ensure a full investigation and full accountability for the killings.

　　He said the United States takes the matter "as seriously as if it were our own citizens and own children who were murdered."  The killing of innocent civilians, he added, "is outrageous and unacceptable" and does not represent "who we are as a country" or represent the U.S. military.

　　Mr. Obama offered this assurance to Americans and the Afghan people. "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.

　　President Obama said he met Tuesday with the U.S. ambassador to Afghanistan, Ryan Crocker, and the commander of U.S. and international forces, Marine Corps Lieutenant General John Allen, who are in Washington.  Mr. Obama said he has "extraordinary confidence" in them and in American forces in Afghanistan.

　　President Obama mentioned that he and visiting British Prime Minister David Cameron would be discussing what he called "the way forward" in Afghanistan.

　　Mr. Obama made a point of addressing his remarks to Americans who recent public opinion surveys show are increasingly opposed to the U.S. military presence in Afghanistan. "Make no mistake.  We have a strategy that will allow us to responsibly wind down this war.  We are steadily transitioning to the Afghans who are moving into the lead.  And that is going to allow us to bring our troops home," he said.

　　The president noted that a total of 33,000 troops will be withdrawn by the end of the year, the full surge force he sent in 2009 to blunt Taliban advances. There are about 91,000 U.S. troops in Afghanistan, with another 34,000 to 37,000 NATO forces.

　　In a CNN interview on Monday, General Allen said there is no contemplation of "any form of an accelerated drawdown" of troops ahead of the 2014 NATO target to end its combat role in Afghanistan.

　　President Obama said on Tuesday that although there is no doubt the United States and its partners face a "difficult challenge," the work of devastating al-Qaida's leadership and denying the terrorist group safe haven will continue.