Hillary Clinton, the US secretary of state, described the latest deployment as "an integrated military-civilian strategy".
"We are convinced that the most critical underpinning of any success we hope to achieve, along with the people and government of Afghanistan, will be looking at where civilian trainers, aid workers, technical assistance of all kinds can be best utilised," she said during a visit to Mexico.
US officials have said success in Afghanistan is impossible without tackling Taliban enclaves in Pakistan, whose government is beset by political turmoil.
Nabi Misdaq, an Afghanistan analyst in Washington, told Al Jazeera that he hoped Obama would not go for a military solution to the conflict, citing a series of US air raids that have caused a number of civilian casualties.
"If these air strikes intensify ... people will take up arms against US troops," he said.
Obama has said previously that the US is losing the war in Afghanistan and the new policy is central top his administration's efforts to turn the conflict around, giving more responsibility to the Afghan government itself.
Obama is to define the objectives of the plan as eliminating the threat from al-Qaeda to undermine or topple US-backed elected governments or to launch attacks on the US, its interests and allies, the Associated Press reported sources as saying.
The strategy is to take a regional approach focusing on counter-terrorism, economic development and offer economic aid to help stabilise Pakistan, where the Taliban has a number of strongholds, officials told the Reuters news agency.
The problems were highlighted by Afghanistan's intelligence chief, who accused Pakistan's spy agency ISI of helping Taliban fighters carry out attacks in his country.
|Obama is set to announce a 'civilian surge' to accompany the troop increase [AFP]
Amrullah Saleh told parliament on Wednesday that ISI provides support to the Taliban leadership council in the Pakistani city of Quetta headed by the group's supreme leader, Mullah Mohammad Omar.
Saleh said the council sends fighters into Afghanistan to attack Afghan and international forces.
Speaking to Al Jazeera on Friday, Daoud Sultanzoy, a member of Afghanistan's parliament, cautioned that internal co-ordination between Pakistan's civilian government and the military-intelligence wings of the state has to be enhanced.
"So far that co-ordination has been very, very anaemic," he said.
"I don't think so far the level of co-ordination has produced any tangible or lasting solutions. All solutions have been periodic and short-lived."
The New York Times also reported on Thursday that Pakistani spy operatives provide money, military supplies and strategic planning guidance to Taliban commanders, with evidence of the ties coming from electronic surveillance and trusted informants.
The report cited American, Pakistani and other security officials who spoke anonymously because they were discussing confidential intelligence information.
A senior officer in the Pakistani spy agency, however, denied the allegations, saying "How is it possible we are co-operating with them and sustaining casualties at the same time?"
The UN is due to hold a conference on Afghanistan in The Hague, the Netherlands, next week, attended by delegates from more than 80 countries.
The gathering was suggested by the US and will also be attended by representatives from Iran, which has said it sees a regional solution to the conflict as vital to securing a lasting peace.
The additional US deployment comes against a backdrop of mounting violence in Afghanistan.
In the latest clash, international forces and Afghan soldiers killed 11 Taliban fighters when a raid in the south turned into a gun battle on Thursday night, US forces said.
The raid had targeted an important Taliban fighter in a village in Helmand province, the US military said in a statement. The forces came under fire from fighters inside a compound as they advanced and returned fire.
Earlier in the day in the same province, nine Afghan policemen were killed by suspected Taliban fighters, interior ministry sources said.
The ministry said the officers were attacked at a police checkpoint in Helmand's Nahri Sarraj district.