WASHINGTON (AFP) - US President Barack Obama on Friday put off a decision on whether to send reinforcements to Afghanistan until after next week's Thanksgiving holiday amid resistance to a troop buildup among key Democrats and criticism from the right. After months of ruminating over the way forward in the eight-year war, Obama will not announce the biggest strategic decision of his young administration until after the holiday, his spokesman Robert Gibbs said.

Thanksgiving is November 26 and Americans traditionally observe a Thursday-to-Sunday break.

Obama had earlier indicated he would end months of deliberations over possible deployment of thousands more troops to the battle-scarred nation ''in the coming weeks.'' He has held a series of closed-door meetings with top advisers -- including General Stanley McChrystal, the commander of the more than 100,000 US and NATO troops already in the country -- to discuss the campaign in Afghanistan and how to achieve US goals there.

McChrystal has asked for up to 40,000 more US troops, warning that Afghanistan could be lost if he does not get them within a year to put down an intensifying Taliban insurgency. Currently, there are 68,000 US troops in Afghanistan. But the top Democrat in Congress observed Friday that there may not be sufficient political support for more troops, especially when Washington had an ''unworthy partner'' in Afghan President Hamid Karzai, who was sworn in Thursday to a second term.

''How can we ask the American people to pay a big price in lives and limbs, and also in dollars, if we don't have a connection to a reliable partner?''
House of Representatives Speaker Nancy Pelosi told National Public Radio in an interview. ''So, you know, the whole thing is let's not just talk about troops. Let's talk about what is the strategy and what are the resources that are needed in that regard.''

Pelosi and other Democrats opposed a similar surge in US troops to Iraq two years ago, arguing at the time that more troops were needed in Afghanistan, the main front in the war against al-Qaeda. Her latest comments reflect the deep discomfort among Obama's Democrats over a deepening military commitment that some fear could sidetrack his presidency, as Vietnam did Lyndon Johnson's in the 1960s.

But the president, recently returned from a trip to Asia where he was dogged by strategy questions about the war, has also been under sustained attack from Republicans who charge that delay is putting US troops at risk.