Campaign officials took aim over the weekend at the recount process, criticizing the U.N.-backed Electoral Complaints Commission doing the tally, The Wall Street Journal reported Monday.
As officials said the announcement of the results would be delayed, Karzai backers demonstrated Sunday against "foreign interference" in the elections.
The recount announcement had been expected Saturday, two months after the vote, which U.N. officials say was tainted by widespread fraud. Most of the ballots believed to be fraudulent were for Karzai, and the recount would likely bring his share to less than 50 percent, which would force a runoff.
The Afghanistan Elections Complaints Commission, which includes foreign representatives, said disagreements with the Independent Election Commission had led to recount delays, Radio France Internationale reported.
U.S. Secretary of State Hillary Clinton has said Karzai is likely to be the winner even if there is a runoff, but noted that backers of his main rival, Abdullah Abdullah, are threatening to protest if there is no follow-up vote.