(Adds U.S. embassy confirmation, comments, paragraphs 1-5, background, paragraphs 16-17)
By Jessica Donati
KABUL, Jan 31 (Reuters) - The United States has cancelled funding for opinion polls in the run-up to Afghanistan's presidential election after an initial poll in December triggered accusations of U.S. attempts to manipulate the outcome, officials said.
A spokesman for the U.S.-funded group Democracy International said on Thursday it and other similar organisations had planned to carry out opinion polls as Afghanistan prepares for the April 5 election.
The U.S. embassy in Kabul later confirmed the funding cut. "Statements by some electoral authorities and candidates' camps suggested that there was ... a perception that the polling results were somehow biased," a U.S. embassy spokesman said.
"In order to avoid any perception - however baseless - of U.S. interference, we have decided to forgo additional U.S.-funded polling regarding the upcoming election," he said.
The cut in funding comes as relations between the United States and Afghanistan have been severely strained over President Hamid Karzai's refusal to sign a bilateral security pact that would enable U.S. troops to stay beyond this year.
The election is seen as crucial to Afghanistan's efforts to build stability, months before most foreign forces are due to withdraw, leaving Afghan forces to battle a resilient Taliban insurgency.
Democracy International programme officer Mohammad Atta said the group had planned three rounds of opinion polls. It published its first results in December but its findings provoked a public outcry and accusations of interference.
"There were a few agencies that were responsible for conducting the polls but all of them have been cancelled at the moment," Atta said.
Karzai has long suspected the United States of having interfered in the last presidential election in 2009 and has warned against further meddling.
Former U.S. defence secretary Robert Gates recently published a memoir appearing to confirm Karzai's suspicion, saying the then top U.S. envoy for Afghanistan and Pakistan had been "doing his best to bring about the defeat of Karzai".
Karzai's spokesman said Washington may try to use polling as a means to influence the outcome of the April election.
"It is now crystal clear that there was interference in the election in 2009," said Aimal Faizi. "It puts the U.S. role behind such funding under question. Why would the U.S. fund surveys on Afghan presidential candidates?"
The United States is Afghanistan's biggest aid donor, despite the difficult relationship with Karzai, but it is committing about 15 percent less for the 2014 election fund than it did in 2009, pledging $55 million.
Democracy International's first poll showed the front-runners to be West-leaning intellectual and former finance minister Ashraf Ghani and former foreign minister Abdullah Abdullah, Karzai's main challenger in 2009.
Hostility between the United States and Karzai, who has served two terms and is not running again, has escalated this month over two key issues.
The first is a plan to release prisoners that Washington says have killed coalition forces and pose a threat to security. The second is a military operation in Parwan province that resulted in a number of civilian deaths.
The United States has threatened to pull out all of its troops unless Karzai signs the security deal promptly. (Editing by Robert Birsel and Raissa Kasolowsky)