Abdullah Abdullah, former Afghan FM speaking with journalists after a press conference in Kabul, Afghanistan, 21 Oct 2009Afghanistan's presidential challenger Abdullah Abdullah says he will not participate in a runoff election next Saturday.

Mr. Abudullah made the televised announcement Sunday to tribal elders at a press conference in Kabul. He did not call for a boycott of the election.

His announcement puts the election process in doubt.  A runoff presidential election between Mr. Abdullah and President Hamid Karzai is scheduled for Saturday.  There has been no immediate response from the president or other government officials about Mr. Abdullah's decision not to run.

Mr. Abdullah had expressed concerns about the credibility of the poll.

Last-minute talks between representatives of Mr. Abdullah and President Karzai were said to have taken place late Saturday.

Afghan President Hamid Karzai (file photo)Mr. Abdullah put forth several conditions this past week to avoid a repeat of the massive fraud that plagued the August 20 presidential election.  The former foreign minister had demanded the removal of top election officials allegedly involved in the fraud, a step Mr. Karzai rejected.

A spokesman for the Afghan election commission, Noor Mohammad Noor, has told VOA that it is too late for Mr. Abdullah to legally withdraw from the vote, which was triggered by a U.N.-backed investigation.

U.S. Secretary of State Hillary Clinton told reporters in Jerusalem that a possible boycott of the vote was Mr. Abdullah's decision to make and would not compromise the legitimacy of the runoff.   Clinton reiterated comments she made earlier in the day in Abu Dhabi, saying such situations are not unusual and have occurred in the United States and other nations.

U.S. officials say President Barack Obama is waiting until after next Saturday's runoff to make a decision about whether to send more U.S. forces to Afghanistan.

Some information for this report was provided by AFP, AP and Reuters.