President Barack Obama warned he would make no "immediate" decision on troops for Afghanistan, a day after the top US military officer said extra US soldiers would probably be needed.
As more and more Americans sour towards the eight-year war, even as expectations mount of a deeper US role in the conflict, Obama promised a painstaking review of strategy before taking such life and death decisions.
Obama spoke as his aides presented lawmakers with a set of proposed benchmarks to measure progress in the US-led fight against an increasingly violent insurgency, amid growing anxiety over the war in Congress.
"My determination is to get this right. I'm going to take a very deliberate process in making those decisions," Obama said after talks at the White House with Canadian Prime Minister Stephen Harper.
"You don't make determinations about resources, and certainly you don't make determinations about sending young men and women into battle without having absolute clarity about what the strategy is going to be.
"We are going to proceed and make sure that we don't put the cart before the horse."
Obama is studying classified recommendations on future strategy by war commander General Stanley McChrystal, who is widely expected to submit a separate formal request to increase the 62,000-strong US force.
He promised that before drawing any conclusions he would seek input from a broad range of government security advisors as well as the US military and its allies in the international force in Afghanistan.
On Tuesday, Admiral Michael Mullen, chairman of the Joint Chiefs of Staff, told the Senate Armed Services committee that more soldiers would likely be needed to subdue the Taliban.
"A properly resourced counterinsurgency probably means more forces and, without question, more time and more commitment to the protection of the Afghan people and to the development of good governance," said Mullen.
The draft list of benchmarks prepared by the administration covers levels of violence, the volume of narcotics trafficking and more subjective criteria such as public perceptions of the Kabul government and its police and judiciary.
It recommended monitoring the level of insurgent-related violence, public perceptions of security, the proportion of the population living in areas under insurgent control, and the percentage of key roads under government control.
The administration will report to Obama, Congress and the American public on the benchmark assessments every three months.
Under the objective of promoting a more capable Afghan government, one benchmark cites the Afghan government's "ability to hold credible elections in 2009 and 2010."
"Well, guess what -- that one is not going to get a glowing rating," said an official on condition of anonymity.
The August 20 presidential elections in Afghanistan were plagued by claims of massive fraud, with European Union observers branding 1.5 million votes as suspicious.
The disputed polls have piled pressure on Obama as he faces mounting skepticism from allies in Congress, including House of Representatives Speaker Nancy Pelosi, who has warned there is little support among lawmakers for more troop deployments.
Powerful Senate Armed Services committee chairman, Democrat Carl Levin, has suggested that Washington should accelerate the pace and scope of training of Afghan forces before sending more US troops.
From the other side, Republicans are warning Obama is acting too slowly.
White House spokesman Robert Gibbs denied the president was stalling in order to avoid confronting Congress with a divisive debate on more troop deployments while he is trying desperately to win passage of his landmark health reform bill.
Obama must also keep a close eye on weakening public support for a war that he maintains was neglected by the previous administration of former president George W. Bush.