WRAPUP 4-Bomb deaths push U.S. toll to worst in Afghan war

(For full coverage of Afghanistan, click on [nAFPAK])

* Bloodiest month for U.S. troops in eight years of war

* Security tight ahead of Nov. 7 presidential run-off

* Speculation of Abdullah pullout continues

* Obama to meet military chiefs on Friday

* U.S. troops decision expected in "coming weeks" (Adds details of toll, payments to Taliban, Obama meeting)

By Maria Golovnina

KABUL, Oct 27 (Reuters) - Eight U.S. troops were killed in southern Afghanistan on Tuesday ahead of a run-off presidential election, the NATO-led alliance said, in the deadliest month for U.S. forces since the start of the war eight years ago.

The mounting violence comes as U.S. President Barack Obama is weighing whether to send more soldiers to Afghanistan to fight a Taliban insurgency that is at its fiercest since 2001.

The eight U.S. soldiers killed in bomb attacks pushed the October death toll to 53, topping the previous high of 51 deaths in August, Pentagon officials said.

The NATO-led force said several soldiers were wounded in the attacks in the south, just a day after 11 U.S. troops and three American civilians died in separate helicopter crashes.

The bombings also killed an Afghan civilian and wounded several service members. No other details were available.

Efforts to stabilize Afghanistan have been complicated by weeks of political tension over an election in August marred by widespread fraud in favor of the incumbent president, Hamid Karzai, forcing a second round set for Nov. 7.

Karzai's camp said on Tuesday a run-off must take place even if his challenger, Abdullah Abdullah, quits the race.

Karzai agreed last week to a run-off under severe international pressure after a U.N.-led fraud investigation annulled a large chunk of his votes in the original election.

Fueling talk he might pull out altogether, Abdullah set out a range of conditions this week. Karzai rejected the demands.

"We should not deprive the people from their right of voting and their right of citizenship," Waheed Omar, Karzai's chief campaign spokesman, told Reuters. "Whether or not the president and Abdullah take part in the run-off or not should not result in depriving the people of what they want."

PAYING TALIBAN TO DEFECT

Abdullah has given Karzai until Saturday to remove the country's top election official and meet other demands but would not say what he would do if his conditions were not met. Abdullah could not be reached for comment on Tuesday.

Concerns about security and a repeat of the fraud that tainted the first round have cast a shadow over the process, prompting some diplomats to suggest that a power-sharing deal between the two contenders looked more practical.

Karzai and Abdullah have so far publicly denied suggestions they could be in talks on a possible deal to share power.

The Taliban has already vowed to disrupt the Nov. 7 poll, highlighting the kind of challenges facing Western powers seeking to turn the tide in the eight-year war.

U.S. soldiers now make up two-thirds of the 100,000-strong coalition force, with Obama considering proposals to send an extra 40,000 troops or a far smaller number.

As part of his review of U.S. strategy in Afghanistan, Obama is set to meet on Friday with Admiral Mike Mullen, the chairman of the Joint Chiefs of Staff, and the heads of the military services, the White House said.

The Friday meeting was "probably getting toward the end" of Obama's decision-making process, spokesman Robert Gibbs said, reiterating that an outcome was likely in the "coming weeks."

To reach out to moderate members of the Taliban, a defense bill Obama will sign into law on Wednesday contains a new provision that would pay militants who renounce the insurgency, Senate Armed Services Committee Chairman Carl Levin said.

The provision sets up a program in Afghanistan similar to one in Iraq in which former fighters were re-integrated into society, Levin told Reuters.

"You got 90,000 Iraqis who switched sides and are involved in protecting their hometowns against attack and violence," said Levin, the leading Senate Democrat on military matters.

The way forward for the United States and its allies is complicated by opposition to a troop build-up from some of Obama's fellow Democrats and opinion polls showing public support for the war waning on both sides of the Atlantic.

In Afghanistan, the protracted election process and prospect of another round has disillusioned many voters, with the onset of the bitter winter adding to the challenges.

"Widespread fraud in Aug. 20 presidential and provincial council polls has deeply undermined the credibility of Hamid Karzai's government, the main beneficiary of the rigging," International Crisis Group said in a statement.

"A flawed second round will hand Taliban insurgents a significant strategic victory and erode public confidence in the electoral process and the international commitment to the country's democratic institutions." (Additional reporting by Golnar Motevalli and Sayed Salahuddin; Editing by Sanjeev Miglani and John O'Callaghan) (maria.golovnina@thomsonreuters.com; Kabul newsroom: +93 799 335 285)) (For more Reuters coverage of Afghanistan and Pakistan, see: http:/www.reuters.com/news/globalcoverage/afghanistanpakistan) (If you have a query or comment about this story, send an e-mail to news.feedback.asia@thomsonreuters.com)