A country gripped by fear: Survey finds majority of Afghans afraid of US troops, 

About 46,000 U.S. troops remain in the country more than 12 years after the invasion triggered by the 9/11 attacks, making Afghanistan the longest conflict in U.S. history.

And while President George W. Bush vowed in 2001 that "the oppressed people of Afghanistan will know the generosity of America and our allies," the survey suggests that vision has failed to materialize despite the hundreds of billions of dollars spent in the country.

Some 77 percent of respondents said they would "be afraid when encountering international forces." 

Respondents were far more confident in their dealings with the Afghan National Police and Afghan National Army. Almost nine-in-ten said the NATO-trained ANA was "honest and fair with the Afghan people" and helped "improve security," while 72 percent felt the same about the police.

Michael Keating, a senior consulting fellow of the Asia program at London's Chatham House think tank, said it was "not that surprising" that many Afghans were wary of coming face-to-face with troops.

"It's not a very relaxing experience," he said. However, Keating also pointed out that Afghans in some parts of the country "do not want [Western forces] to leave."

The Asia Foundation conducted face-to-face interviews with a total of 9,200 Afghans, with respondents living in all of the country's 34 provinces. The San Francisco-based organization has carried out the survey annually since 2004.

According to the poll, 59 percent of respondents said they would "experience some level of fear" when voting in an election. The Taliban has targeted polling stations in recent years. The country will elect a new president in April.

But Geeta, a 22-year-old teacher in Sheberghan Jawzjan, said she believed the ballot box was crucial to "bring a change" to Afghanistan.

"Our country is in need of educated and honest leaders. And in order to bring a person of the mentioned qualities into power, I voted for the candidate of my choice," she told NBC News. "I have also encouraged all my friends to go to polls and vote."

A clear majority of respondents – 68 percent – said they would be afraid to participate in a peaceful demonstration.

Geeta said she had demonstrated to remove a local governor who was not living up to some residents' expectations.The survey has been released as Afghanistan remains locked in negotiations with the U.S. about the bilateral security agreement which will shape America's military presence in the country after 2014.

Without an agreement, the U.S. could withdraw all its troops and leave the Afghan administration, currently led by President Hamid Karzai, to fight the Taliban alone.

More than 2,100 American troops have died and almost 20,000 have been wounded during the conflict, according to the Department of Defense.