The White House has said that it will take no decision on sending more troops to Afghanistan until it determines the new government is a "true partner", BBC reported.
White House Chief of Staff Rahm Emanuel told CNN TV it would be "reckless" to take such a decision without a thorough analysis of the new government.
Washington is debating a request for 40,000 more troops in Afghanistan.
Results from an investigation into fraud claims in the presidential poll are due in the next few days.
It is expected to reveal that incumbent President Hamid Karzai did not achieve more than the 50% of votes needed to avoid a second round.
Mr Karzai insists he won the 20 August vote but EU observers say that as many as one in four votes cast was suspicious.
Foreign officials - including US Secretary of State Hillary Clinton and France's Foreign Minister Bernard Kouchner - have been pressing Mr Karzai to accept that he might have to face a run-off.
Speaking to CNN, Mr Emanuel said the US would want first to be sure that the government was capable of becoming a "true partner" able to govern the country.
"It would be reckless to make a decision on US troop level if, in fact, you haven't done a thorough analysis of whether, in fact, there's an Afghan partner ready to fill that space that the US troops would create and become a true partner in governing the Afghan country," he said.
Gen Stanley McChrystal, the US and Nato commander in the country, has recommended sending the extra troops as the US reviews its strategy.
But Mr Emanuel said that the number of soldiers deployed in the country was secondary to whether or not they could work alongside an effective Afghan administration.
"The question does not come how many troops you send, but do you have a credible Afghan partner for this process that can provide the security and the type of services that the Afghan people need?" he told CNN's State of the Union programme.
Results delayed
Initial results from August's election gave Mr Karzai 55% of the votes, with his nearest rival, Abdullah Abdullah, getting 28%.
But the UN-backed Electoral Complaints Commission (ECC) launched an investigation into the vote following allegations of widespread electoral fraud.
It will report to the Independent Election Commission (IEC), which could adjust the final tally, bringing Mr Karzai's vote total below 50% and triggering a run-off.
Officials say Mr Karzai is furious over the prospect of facing a second round, threatening to delay or block attempts to hold a second round.
He has refused to accept the ECC's findings before they are released.
The ECC had been expected to announce its findings on Saturday. But the reported confrontation with Mr Karzai may delay the official announcement of results.