Washington: US Secretary of State Hillary Clinton has expressed "deep regret" over the shooting incident in Afghanistan in which a US soldier killed 16 Afghan civilians, which also included women and children.

"This has been very personally painful to me and to the president (Barack Obama). It does not represent who the US is, who the American people are," Clinton said after meeting visiting Afghan Foreign Minister Zalmai Rassoul at the State Department.

The shooting took place on March 11 in Zangabad village of Panjwai district when a US soldier walked out of a military camp in Kandahar province, broke into three houses and began shooting indiscriminately which led to the killing of 16 civilians, including nine children and three women and injured nine others.

Clinton said Washington remains committed to a political solution as the war in Afghanistan entered its 11th year.

A series of events, including the burning of the Quran by US soldiers and the recent killing of Afghan civilians, and the Taliban's announced suspension in talks with the US, have complicated efforts by NATO-led coalition forces to hand over security to Afghan forces and end combat mission by 2014, as reported.

"What the Taliban do is up to them. We have been clear, we are prepared to continue discussions and our goal is to open the door so that Afghans can be negotiating among and between themselves," Clinton said."Any negotiation must require the Taliban to break ties with Al Qaeda, to renounce violence and to abide by Afghanistan's constitution, including the protections of women and minority rights," she said.