Karzai has regularly criticised the levels of civilian deaths in Afghanistan
Afghan President Hamid Karzai has criticised a US military operation which killed at least 16 people in eastern Afghanistan.
Mr Karzai said most of those killed were civilians, adding that such deadly incidents strengthened Taleban rebels and weakened Afghanistan's government.
Women and children were among those killed, Mr Karzai said.
The strike was the first controversy in Afghanistan involving US troops since US President Barack Obama took office.
In a statement, the president said two women and three children were among the dead in the attack, which the US said targeted a militant carrying a rocket-propelled grenade (RPG).
Speaking at a ceremony for newly-graduated officers entering Afghanistan's armed forces, Mr Karzai said he hoped the country's own military would soon be able to shoulder more of the burden of fighting the Taleban.
"Our goal is to improve our army and have the ability to defend our country ourselves as soon as possible, and not have civilian casualties anymore as we again had yesterday," he said.
The Afghan president has been a frequent critic of the numbers of innocent Afghans killed by military operations by international forces in the country.
Just last week he again called on US-led and Nato troops in his country to do more to reduce civilian casualties.
Reacting to the first flare-up since Mr Obama's inauguration in the US, Mr Karzai said Afghanistan's defence ministry had sent Washington a plan to give Afghan forces more oversight over US military operations.
The same letter has also been sent to Nato headquarters, the Associated Press said.
A statement from Mr Karzai's office said continued civilian deaths "will not bear any progress in the war against terrorism".
In response, a US military spokesman said there were plans to jointly investigate the incident with the Afghan government.
Originally the US said all of the dead, including one woman, had been militants who opened fire after its troops surrounded a compound in Mehtar Lam, about 60km (40 miles) east of the capital, Kabul.
"The people who were killed today were running around, manoeuvring against our forces, and we killed them," said Col Greg Julian.
Eleven were killed by gunfire; four others by close air support, it added.
However, officials in Laghman have since said there were civilians among the dead, a viewpoint now backed by the country's president.
The US military insists that it goes to considerable lengths to avoid civilian casualties.
But the BBC's Ian Pannell in Kabul says that as the US increases its military presence, it will be increasingly difficult to do so.