Maj. Michael Johnson, a NATO forces spokesman, said the cause of the "hard landing" Saturday was being investigated. He said he couldn't disclose what kind of helicopter went down or whether it was part of a larger operation in the region, the Los Angeles Times reported.
Taliban officials claimed they shot the helicopter down and killed its crew, which it said were French.
"The forces had come to the area to attack on mujahedin strongholds, but they faced furious attacks," said Taliban spokesman Zabiullah Mujahid.
Helicopters and other aircraft are used to transport and supply troops in Afghanistan's mountainous regions where paved roads are scarce.
Officials said fighting has increased in eastern Afghanistan in recent days. Saturday insurgents killed two Afghan police officers. Two other officers were wounded.
Friday, a NATO soldier was killed in an insurgent attack in eastern Afghanistan. Another NATO soldier was killed in the same area Thursday by an improvised explosive device.