*Option for 30,000-plus troops gaining aides' support
*Obama visits graves of troops killed in Iraq, Afghanistan
WASHINGTON, Nov 11 (Reuters) - U.S. President Barack Obama convened his war council on Wednesday for talks considered critical to his deliberations on boosting troop levels in the increasingly unpopular war in Afghanistan.
Though the White House insists Obama has yet to decide among the four strategy options he is considering, U.S. officials said there was growing support among his top advisers for deploying 30,000 or more additional troops to Afghanistan.
Obama held the closed-door review, the eighth in a series of such meetings, as a new opinion poll showed a growing number of Americans believe the war in Afghanistan is not going well and disapprove of his handling of the situation.
Record combat deaths have eroded U.S. public support for the eight-year-old war, and a decision to expand troop levels could become a political liability for Obama ahead of congressional elections next year.
With aides saying Obama is still weeks away from a decision, it remains unclear where Obama stands. Republican critics have accused him of dithering, but the Democratic president says he is taking the time needed to get it right.
At a ceremony honoring war veterans at Arlington National Cemetery, he made no direct mention of Afghanistan -- which his aides once called the "good war," in contrast to the Iraq war launched by his predecessor George W. Bush in 2003.
Obama walked in the rain among the graves of troops killed in Iraq and Afghanistan and later paid tribute to the U.S. military's sacrifices.
"For the better part of a decade, they have endured tour after tour in distant and difficult places. They have protected us from danger," Obama said in his Veterans Day address.
OPTION GAINING SUPPORT
Defense Secretary Robert Gates and Chairman of the Joint Chiefs, Admiral Mike Mullen, are among top officials who have privately signaled support for a 30,000-plus troop increase in Afghanistan to battle a resurgent Taliban and its al Qaeda allies, the officials said.
If bolstered by smaller commitments of trainers from NATO allies, that would come close to the 40,000 requested by General Stanley McChrystal, the top U.S. and NATO commander in Afghanistan, as necessary to avert failure there.
But the officials said some differences of opinion might remain between Gates and military chiefs over details. A spokesman for Gates declined comment.
Obama is considering options that include sending roughly 15,000, 30,000 or 40,000 more troops to Afghanistan to try to stem Taliban gains, officials said. Currently, there are nearly 68,000 U.S. troops and 40,000 allied forces in Afghanistan.
Public approval of Obama's handling of Afghanistan has dropped from 49 percent in July to 36 percent in November, according to a poll released on Wednesday.
The Pew Research Center survey showed that 57 percent now say the military effort in Afghanistan is going either not too well or not well at all, up from 45 percent in January.
The poll found the U.S. public divided over U.S. troop levels in Afghanistan, with 40 percent saying it should be lowered, 32 percent saying it should be increased and 19 percent saying it should be kept where it is.
The poll was a telephone survey of 2,000 people conducted between Oct. 28 and Nov. 8 with a sampling error of plus or minus 3 percentage points. (Additional reporting by Adam Entous and Alister Bull, editing by Vicki Allen)
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