Washington, March 13 US President Barack Obama Sunday called Afghan President Hamid Karzai to express his "shock and sadness" at the killing of Afghan civilians.
A US soldier Sunday morning walked out from his military base in Kandahar province and opened fire, killing 16 civilians, including women and children.
"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.
Obama also "reaffirmed our deep respect for the Afghan people and the bonds between our two countries," Xinhua quoted the statement as saying.
President Obama described the incident as "tragic and shocking", saying it "does not represent the exceptional character of our military and the respect that the United States has for the people of Afghanistan".
The incident came as relations between Washington and Kabul have been strained over the burning of copies of Quran by US troops last month.
Karzai condemned the killing as an "unforgivable action", demanding an "explanation" from Washington.