KABUL - Afghan President Hamid Karzai's election rival Abdullah Abdullah will announce on Sunday whether he will take part in next week's disputed run-off vote, his campaign said after speculation mounted he will pull out.

Abdullah canceled a planned trip to India on Saturday, just before a deadline he had given Karzai to sack Afghanistan's top election official was to expire.

Afghanistan has been racked by weeks of political uncertainty after widespread fraud marred the first round, with security another major concern after a resurgent Taliban vowed to disrupt the November 7 run-off vote.

With Afghanistan's political future hanging in the balance, U.S. President Barack Obama is also weighing whether to send thousands more troops to Afghanistan. Obama met U.S. military leaders in Washington on Friday as part of a strategy review.

Abdullah's campaign team issued a short statement on Saturday saying the former foreign minister had called a loya jirga, or grand assembly of elders, for 9.30 a.m. on Sunday (1:00 a.m. EDT).

Dr Abdullah Abdullah will a give speech about the election and he will announce his decision in the loya jirga tent, the statement said.

Abdullah's aides earlier said he had canceled the trip to India because of uncertainty over the election.

Western officials have noted that Abdullah has not opened any campaign offices in Afghanistan since the run-off was called last week. Neither candidate has campaigned openly.

The signs are there. (Abdullah's) not doing any campaigning. Everyone is looking at the two camps and willing them to do some form of accommodation that will avoid a run-off, one Western diplomat, who asked not to be identified, told Reuters.

Diplomats and analysts have said that, according to the constitution, it was possible the run-off might go ahead with Karzai as the only candidate if Abdullah pulls out. They fear that would have a serious impact on the government's legitimacy.

If Abdullah boycotts, voter turnout will be very low and Karzai will be declared winner but with a very low legitimacy, said Haroun Mir, a Kabul-based analyst and director of Afghanistan's Center for Research and Policy Studies.

Speaking in Abu Dhabi, U.S. Secretary of State Hillary Clinton said such a situation was not unprecedented. I don't think it has anything to do with the legitimacy of the election. It's a personal choice which may or may not be made, she said.


Talk of a possible power-sharing deal between Karzai and Abdullah has also grown as a possible solution to the deadlock.

The U.S. embassy in Kabul said it was a matter for Karzai and Abdullah to decide if they could come up with a constitutionally sound solution that was acceptable to Afghans.

Western diplomats have said privately Abdullah may have overplayed his hand with last week's ultimatum to Karzai, which included a demand to sack three ministers in a bid to avoid a repeat of the first-round fraud.
Karzai has already indicated he would not give in to Abdullah's demand. Abdullah has not said yet what he would do if the officials were not sacked.

Citing an unidentified Western source it said was close to the Afghan leadership, CNN reported on Friday that talks between Karzai and Abdullah had broken down and that Abdullah would likely pull out.

Neither Karzai nor Abdullah would comment on those meetings but behind-the-scenes diplomatic efforts to convince them to work together to break the deadlock increased this week.

The run-off was triggered when a U.N.-led fraud investigation found widespread fraud, mainly in favor of Karzai, had been committed during the August 20 first round.

The United States already has about 70,000 troops in Afghanistan and the decision to send more hinges on whether the Afghan government is seen by U.S. lawmakers and the public as a legitimate and viable partner.

Obama's predecessor, George W. Bush, said Afghanistan faced a return to a brutal tyranny if the Taliban, al Qaeda and their militant Islamist allies were allowed to return to power. Bush was speaking at the leadership summit in New Delhi Abdullah had been due to attend.

Many commentators and Western diplomats believe Karzai will likely win the run-off, adding pressure on Abdullah to withdraw for the sake of stability.

It would also avoid the mobilization of thousands of foreign troops that would be needed to help secure polling stations after poor security and Taliban threats cut voter turnout in August.

Karzai's support mainly comes from Pashtuns, Afghanistan's largest ethnic group and the country's traditional rulers, in the south and east where the Taliban-led insurgency is strongest.

The Taliban have called on Afghans to boycott the run-off and have vowed to disrupt the poll, their threat underlined on Wednesday by a suicide attack on a Kabul guest-house used by the United Nations in which five foreign U.N. staff were killed.

(Additional reporting by Andrew Quinn in ABU DHABI and Matthias Williams in NEW DELHI; Editing by Paul Tait)