WASHINGTON - The United States faces tremendous challenges in its rebuilding effort in Afghanistan, probably a much tougher job than the reconstruction in Iraq, federal auditors warn. The auditors, quoted in Thursday's Washington Post, took the American-built projects in Iraq that local people couldn't run themselves as an example of an issue that could be even more problematic in Afghanistan. In Afghanistan, three-quarters of the population is illiterate and the average annual income is 800 US dollars. The country has few paved roads, no railway and only a handful of airports with paved runways. By contrast in Iraq, 74 percent of the population is literate, the average annual income is 4,000 dollars, and the nation has a network of roads, railways and airports. "Afghanistan has a much lower absorptive capacity for investment," said Stuart W Bowen, the special inspector general for Iraq reconstruction. Similarly, Pentagon officials have expressed a key concern that the Afghan national security forces they are training lack the capacity to perform the intelligence and data gathering necessary for national security. Arnold Fields, the special inspector general for Afghanistan reconstruction, noted concerns of corruption, abuse and inadequate oversight of the tens of billions of US dollars appropriated for Afghan reconstruction. The reconstruction effort in Iraq is winding down as the effort in Afghanistan is ramping up, with 32 billion dollars appropriated since 2001 and more coming. Meanwhile, the United States must improve its intelligence gathering in Afghanistan, the US Director of National Intelligence Dennis Blair said Thursday. "We need to ramp up the level of intelligence support in Afghanistan," Blair told journalists. "We know a heck of a lot more on Iraq than on Afghanistan," he said, adding the United States particularly needed "a granular understanding of local power structures."