Civilian casualties in Afghanistan must be reduced, the newly appointed commander of US and Nato-led troops Gen Stanley McChrystal has told the BBC.
He said both preventing and investigating incidents where civilians were hit would be a priority.
Earlier, a UN report said the number of civilians killed so far this year had risen 24% on the same period last year.
The UN said insurgent bombings and air strikes by international forces were the biggest killers.
There has been widespread concern in Afghanistan about civilian death tolls.
In June the US military called for better training in an effort to reduce the numbers of civilian deaths.
The Taliban also issued a new code of conduct earlier this week which says fighters should minimise civilian casualties.
Gen McChrystal, the new commander of US and Nato-led troops in Afghanistan, said civilian casualties were "deeply concerning" and something he "would love to say we'd get to zero".
He said he was trying to build this into the culture of his forces, but admitted it was very hard to balance this with their own protection.
"It's very hard because it's a balance for the young soldier on the ground, who is in combat. One of the assets that he has that might save his life might be air power or indirect fire from artillery or mortars and we don't want to take away that protection for him," he said.
But that "must be balanced against the possibility of hurting anyone".
He said he wanted his forces to be seen both to work actively to prevent civilian deaths, and to investigate civilian deaths openly when they did occur.
On the possibility of talks with the Taliban after presidential elections in August, Gen McChrystal said the US was willing to talk to anyone ready to seek a political solution - including local fighters and senior Taliban figures.
But he pointed out that ultimately those decisions were up to the Afghan government.
There is enormous pressure on the new commander, says the BBC's Lyse Doucet in Kabul.
The US defence secretary Robert Gates has made it clear that foreign forces have a year to show clear progress on the security front or will lose support here and at home.
Civilian targets
The report, by the UN Assistance Mission in Afghanistan (Unama), says insurgents were responsible for more deaths than government-allied forces.
But it also notes that two-thirds of the deaths caused by government-allied forces came in air strikes.
The rising death toll was partly due to the fact that militants were deliberately basing themselves in residential districts, the report's authors concluded.
The increasingly sophisticated tactics used by insurgents were also highlighted.
This is the third year the UN has counted civilian deaths and the numbers have risen each year.
Election fears
The UN warned more civilians may be killed in the coming weeks as militants fight back against a major offensive by US forces ahead of key elections next month.
Elections are due to take place amid tight security on 20 August, when President Hamid Karzai is hoping to secure a second term.
However, in the past week alone there have been two attacks on Afghan election campaigns.
On Tuesday a campaign manager for presidential candidate Abdullah Abdullah was wounded when his vehicle was attacked in Laghman province.
Two days earlier there was an assassination attempt on Mohammed Qasim Fahim, a running mate of Mr Karzai.
