KABUL, Afghanistan — NATO said Wednesday that it killed too many Afghan civilians during fighting last year against resurgent Taliban militants, but that the Western alliance was working to change that in 2007.

The acknowledgment came one day after President Hamid Karzai's latest plea for foreign forces to use maximum caution following the deaths of two civilians, reportedly involving NATO troops.

"The single thing that we have done wrong and we are striving extremely hard to improve on (in 2007) is killing innocent civilians," Brig. Richard E. Nugee, the chief spokesman for NATO's International Security Assistance Force, told a news conference.

Nugee said the alliance has been reviewing for several weeks measures to reduce the number of civilian casualties, without elaborating.

NATO forces were accused of killing dozens of civilians last year in airstrikes, battles and other shootings, prompting Karzai to issue several pleas for international forces to use greater caution in their operations.

Still, Nugee said NATO forces had killed far fewer civilians than the Taliban, which launched a record number of roadside and suicide bombs last year.

"There is absolutely no comparison to be made," he said. "The Taliban are killing significant numbers of their own people and showing no remorse at all."

Militants launched 117 suicide attacks in 2006, about a sixfold increase over 2005, killing 206 Afghan civilians, 54 Afghan security personnel and 18 NATO soldiers, according to NATO numbers.

Karzai, in a statement Tuesday, expressed "deep regret" over the deaths of two civilians in Nangarhar province a few days earlier. The Afghan Interior Ministry had said foreign troops were involved, although NATO spokesman Maj. Dominic Whyte said no NATO or U.S.-led coalition soldiers were responsible.

"Once again, I urge the Afghan and international forces to ensure greater coordination between themselves and to practice maximum caution during their anti-terrorist operations so that civilians are not harmed," Karzai said.

Karzai last month broke down in tears during a speech in which he recounted stories of children maimed by bombings.

"We can't prevent the terrorists from coming from Pakistan, and we can't prevent the coalition from bombing the terrorists, and our children are dying because of this," he said.

NATO airstrikes in the Panjwayi district of southern Kandahar province in October reportedly killed dozens of civilians, including 20 members of one family, according to Afghan authorities.

A joint Afghan-NATO investigation into the incident has never been released. The New York Times has reported previously that the investigation found that 31 civilians were killed.

Nugee said that commanders have looked at the report "in very fine detail."

"While it has not come out publicly, it has made quite an impact on this headquarters," he said.

After the October incident, Human Rights Watch said NATO wasn't doing enough to prevent civilian casualties in Afghanistan.

Sam Zarifi, the group's Asia research director, said NATO "should reconsider the use of highly destructive but hard-to-target weaponry in areas where there is a clear risk of considerable civilian casualties," referring to aerial bombs and missiles that can easily miss their target.

The human rights group also criticized the Taliban and other insurgents for placing civilians at risk "by using populated areas to launch attacks on NATO and Afghan government forces."