But Richard Boucher, the Assistant Secretary of State for South and Central Asia, disputed the reports' findings and offered the Senate hearing a more optimistic assessment, reports the Financial Times.
Mr Boucher said the strategy in Afghanistan was to improve government services at the local and provincial level, and that the increase in suicide bombings was the Taliban's response to its failure to win or hold territory in conventional military clashes.
"We have had many successes but we have not yet enjoyed success and that's what we have to focus on," he said, arguing against focusing too much on a "snapshot" view of Afghanistan's weak government, increasing drugs trade and insurgency. Nato officials and their civilian counterparts have worried for over a year about the supposed lack of an overarching strategy.
But to date many attempts to craft such a strategy have failed, including French president Jacques Chirac's 2006 proposal for a "contact group" on Afghanistan and this year's attempt to install Paddy Ashdown, the former United Nations high representative to Bosnia, as international envoy to the country. Nato's formal mandate of bolstering the authority of the government of President Hamid Karzai is often problematic, because he appears to lack authority in areas outside Kabul.