US troop numbers are set to rise in Afghanistan this year
The incoming US general in charge of troops in Afghanistan says his priority will be to review all Nato operations in a bid to reduce civilian casualties.
Gen Stanley McChrystal said the population needed protection from the enemy, but also "from the unintended consequences of our operation".
He spoke as regional commander Gen David Petraeus said insurgent attacks are at their highest level since 2001.
Last week saw more than 400 attacks, eight times the rate of January 2004.
Gen Petraeus said the numbers of insurgent attacks was expected to increase as troops target their bases and safe havens.
There are currently more than 70,000 foreign troops in Afghanistan, mostly under Nato command.
The Obama administration plans to send an additional 21,000 troops.
Speaking to BBC Radio 4's Today programme, Gen McChrystal said counter-insurgency was key.
"When we are in position, one of the things we'll do is review all of our rules of engagement and all the instructions to our units, with the emphasis that we are fighting for the population.
"That involves protecting them both from the enemy and from unintended consequences of our operation, because we know that although an operation may be conducted for the right reason, if it has negative effects it can have a negative outcome for everyone."
Correspondents say civilian casualties are causing growing public outrage throughout Afghanistan and friction between the US and Afghan governments.
To combat the negative sentiment the Obama administration has made it clear it also plans to devote more resources to the information war in Afghanistan in response to an aggressive media campaign by Taliban insurgents.
US Defence Secretary Robert Gates is confident the new commander will "devote the resources necessary" to improve how the military explains its mission, his press secretary Geoff Morrell told the French news agency AFP.
Among the 400 senior staff Gen McChrystal will bring with him to Afghanistan will be Adm Gregory Smith who has been assigned to improve communications efforts.
This may include jamming Taliban radio broadcasts designed to threaten locals and undermine their confidence in the ability of the western military forces.
On the civilian side, the US government plans to deploy dozens of advisers to offer public relations advice to Afghan staff in ministries and governor's offices including designing public information campaigns, according to a document seen by AFP.
Gen McChrystal said his aim was to prevent the re-emergence of al-Qaeda and the Taliban in Afghanistan, blocking any future "safe havens" in Afghanistan.
Asked if it would be a long-term operation in Afghanistan, Gen McChrystal said: "It will go on until we achieve the kind of progress we want to achieve.
"It won't be short."
He said he looked forward to continuing and increasing the partnership with British forces in Afghanistan.
Without expressly calling for long-term reinforcements he made it clear that any increase in British troops numbers would be very welcome.
With his experience of going after Saddam Hussein and other high-profile leaders, Gen McChrystal said he was not prepared to predict what would happen to Osama bin Laden, although he did say there was "a requirement to go after significant leaders".
"If we win this effort it will be because we protected the population and going after the high-value enemy targets will just be a supporting effort to do that."
Gen Petraeus, who oversees US military operations across the Middle East, as well as in Afghanistan and Central Asia, said attacks had worsened over the past two years and reached a new high in the past week.
He said difficult times ahead were partly because US forces were targeting what he called militant sanctuaries and safe havens.
Speaking in Washington, Gen Petraeus, who spearheaded the US "surge" strategy while commander in Iraq, said there would be new difficulties and more clashes as the international presence in Afghanistan increased.
"Some of this will go up because we are going to go after their sanctuaries and safe havens as we must," Gen Petraeus, who heads US Central Command, said in a speech at the Washington think-tank Center for a New American Security.
"But there is no question the situation has deteriorated over the course of the past two years in particular and there are difficult times ahead."
Gen Petraeus said he was facing challenges in Afghanistan which had not featured during his time in Iraq and which included difficulties in relations with local people.
He stressed the need for "being good partners and good neighbours and having enormous concern, needless to say, about civilian casualties in everything we do".