US President Barack Obama plans to dispatch thousands more military and civilian personnel to Afghanistan on top of the 17,000 fresh US combat troops already ordered, sources have said.
Mr Obama, unveiling his revamped strategy for the mission, will also call for increased aid to neighbouring Pakistan - as long as its leaders confront militants in the border region.
"It is an integrated military-civilian strategy," Secretary of State Hillary Clinton told reporters in Monterrey, Mexico.
"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."
Mr Obama will broadly define US objectives as eliminating the threat from al Qaida to undermine or topple American-backed elected governments or to launch attacks on the United States, its interests and allies, said the sources.
The new plan identified al Qaida as the target in a larger network of insurgents who threaten US and allied forces in Afghanistan, often from sanctuaries across the border in Pakistan. The additional 4,000 troops devoted to training and advising the Afghan armed forces would head to Afghanistan this spring and summer. They come on top of about 17,000 combat and support troops Mr Obama wants in place by the end of the summer.
White House press secretary Robert Gibbs said Mr Obama's top military advisers have briefed key politicians on the strategy.
Senator Carl Levin, chairman of the Armed Services Committee, said the training group is needed because there are not enough US military advisers currently deployed.
Mr Levin, a Democrat, said: "We've got to increase the size (of the Afghan army) much more quickly than contemplated and the trainers are the key to that."
Senator John McCain, a Republican, said it seemed like a viable strategy as long as the manpower is there. "I know we need more than the 17,000," he said.
