The United States said Friday it was troubled by Afghan President Hamid Karzai's "preposterous" accusations that foreigners rigged last year's controversial elections, according to dpa. Karl Eikenberry, the US ambassador to Afghanistan, met with Karzai on Friday to "clarify" the remarks, which came just days after President Barack Obama made his first visit to Afghanistan, a country that is central to US efforts to defeat al-Qaeda. "We're troubled by the comments," State Department spokesman PJ Crowley told reporters in Washington. "Suggestions that somehow the international community was responsible for irregularities in the recent election is preposterous." Karzai on Thursday blamed US and European Union election monitors for orchestrating "widespread fraud" in the August presidential election. He said the West was also trying to stop the next round of parliamentary elections slated for September. The remarks came as the United States and NATO are stepping up their military efforts in Afghanistan to defeat the militant Taliban and al-Qaeda remnants. Obama ordered an additional 30,000 troops to the country in December. Relations between the West and Karzai have steadily deteriorated since the disputed August election. UN monitors exposed massive fraud in the poll and threw out one-third of Karzai's votes, forcing a run- off. Karzai was eventually declared the winner because his chief opponent dropped out of the run-off. Karzai accused US diplomat Peter Galbraith, the former deputy United Nations envoy in Afghanistan, and French General Philippe Morillon, head of EU's monitoring mission, of leading the vote rigging.