Seeking to defuse tensions within Afghanistan, President Obama on Sunday called Afghan President Hamid Karzai to express his shock and sadness at a U.S. Army sergeant's killing of at least 16 civilians there.
Earlier, Karzai condemned the rampage as "intentional murders" and demanded an explanation from the United States.
The soldier reportedly walked more than a mile from his base and methodically shot and killed the civilians -- nine of whom were children -- in a rural stretch of southern Afghanistan early Sunday. The Obama administration already is seeking to mitigate the fury among Afghans over Americans last month burning Muslim holy books on a base in Afghanistan.
"President Obama extended his condolences to the people of Afghanistan, and made clear his administration's commitment to establish the facts as quickly as possible and to hold fully accountable anyone responsible." the White House said in a statement. "The president reaffirmed our deep respect for the Afghan people and the bonds between our two countries."
The unidentified solider has been detained and the Army is investigating. Witnesses in Afghanistan have contended several other soldiers were involved, although the Army has denied those accounts.
The incident has sparked political outrage and renewed questions about the challenges in Afghanistan.
Newt Gingrich said Sunday that the U.S. mission there is "not doable," while Rick Santorum called the incident "horrible." Senate Majority Harry Reid, D-Nev., said Afghanistan is "just not a good situation."
"Our troops are under such tremendous pressure in Afghanistan," Reid said Sunday. "It's a war like no other war we've been involved in. ... We're moving out, as the president said. I think it's the right thing to do."