Sixty percent of Americans believe the war in Afghanistan is not worth its costs, and nearly the same number advocate an early US pullout from the country, a new poll showed.

The survey by ABC News and The Washington Post indicated that the number of skeptics was nearly double the 35 percent saying the decade-long effort has warranted the expense and lost lives.

Overall, 54 percent of all Americans want to pull out US troops from Afghanistan even if the Afghan army is not adequately trained to carry on the fight, according to the survey.

About six in 10 Democrats and independents back this position, the poll showed. In the Republican Party, four in 10 take the same position.

Just 30 percent of Americans believe that most Afghans endorse the current US strategy in their country, the survey found.

The United States and its NATO allies plan to pull out their troops from Afghanistan by the end of 2014 and hand over security operations to the Afghan army.