The US envoy to Afghanistan expressed his 'deep concern' over possible deployment of thousands of new troops to the country.
In a leaked cable, Ambassador Karl Eikenberry expressed doubts about the competence of President Hamid Karzai's government.
Mr Eikenberry resigned his Army commission to take the job as US ambassador in Kabul earlier this year, and his is an influential voice among those advising President Barack Obama on Afghanistan.
Mr Eikenberry sent multiple classified cables to Washington over the past week questioning the wisdom of adding forces when the Afghan political situation is unstable and uncertain, according to an official familiar with the cables.
Mr Eikenberry made the point that the administration should step cautiously in planning for any troop build-up while there are still so many questions surrounding Mr Karzai, the official said.
Mr Eikenberry is the front line US official dealing with President Karzai, the US-backed leader whose administration was stained by corruption and mismanagement. It was a visiting senior senator, Democrat John Kerry of Massachusetts, who was instrumental in persuading Mr Karzai last month to accept the findings of a UN panel that his re-election vote in August was too marred by fraud to stand.
Mr Karzai agreed to a second round of voting but was elevated to a second term as president without a run-off election when his challenger dropped out. Since then, US officials have been alarmed at some of Karzai's remarks and the lack, so far, of meaningful steps to clean house.
Mr Eikenberry's objections were a wild card in the midst of what had appeared to be the final days of Mr Obama's long decision-making process on how to revamp US strategy in the eight-year war. Mr Eikenberry has participated in some of Mr Obama's war council sessions over the past several weeks.
A senior US official said Mr Obama rejected all four options presented to him at what had been expected to be the last of those sessions yesterday. Those options started from the premise that some addition of US forces is necessary, and included ways that Mr Obama could meet or nearly meet war commander General Stanley McChrystal's preference for about 40,000 additional troops.
It is not clear whether Mr Eikenberry's objections played a part in mr Obama's decision not to accept any of the choices prepared by military planners.
At his Senate confirmation hearing in March, Mr Eikenberry underscored what he called the urgency of the requirement to turn around the war effort, which has evolved into a stalemate in key parts of Afghanistan as the Taliban-led insurgency has gained clout. "Time is of the essence," he said. "There will be no substitute for more resources and sacrifice."
He said Europeans, for example, should be expected to provide more mentors for Afghan police trainees. Another key to success, he said, is getting more civilian experts such as agriculture specialists and justice experts who can help reduce Afghanistan's dependence on the illicit narcotics trade.
Mr Eikenberry was the top US military commander in Afghanistan for two years before moving to Brussels to be deputy chairman of Nato's military committee in 2007. He had served one previous tour in Afghanistan.
AP