Clinton shocked by Afghan slaughter

US Secretary of State Hillary Clinton says she is 'shocked and saddened by the killings of innocent Afghan villagers' by a US soldier over the weekend.

'This is not who we are and the United States is committed to seeing that those who are responsible are held accountable,' she told reporters on the sidelines of talks at the United Nations about Syria on Monday.

She said the attack, allegedly carried out by a US soldier who walked off his base in southern Kandahar province and broke into three village homes before dawn on Sunday, was 'terrible', 'awful'.

She added she could not 'even imagine the impact on the families who were subject to this attack and the loss of children'.

'This terrible incident does not change our steadfast dedication to protecting the Afghan people and to doing everything we can to build a strong stable Afghanistan,' Clinton added.

'We recognise that an incident like this is inexplicable and will certainly cause many questions to be asked,' the US top diplomat said.

'But I hope that everyone understands in Afghanistan and the rest of the world that the United States is committed to seeing Afghanistan continue its move toward a stable, secure, prosperous, democratic state.'

She acknowledged, however, that after the burning of Korans last month sparked widespread protests 'we have had a difficult and complex few weeks in Afghanistan'.