Afghanistan's approaching winter weather may join threats of violence and allegations of election fraud as a major problem in choosing a president.
In an interview with the Reuters news agency, Afghanistan's chief electoral officer said if a runoff election is required, it needs to happen before the third week of October.
Daoud Ali Najafi says winter snow will make a runoff later in the year impossible.
Preliminary returns released Wednesday show Afghan President Hamid Karzai with 54 percent of the vote. That is more than the 50 percent needed to avoid a runoff.
But a U.N.-backed electoral oversight group has ordered a partial recount because of fraud allegations. And Najafi says the group should speed up its fraud investigation, or the climate of mainly-rural Afghanistan will force a long delay of any runoff.
Meanwhile, a U.N. spokesman tells Reuters he is confident the recount can be completed in time for a runoff this year, if needed.
Some information for this report was provided by Reuters.