The crash occurred "due to a non-hostile incident" about 4:15 p.m. near Camp Resolute Support in Kabul Afghanistan, the military said in a press release.
The United States did not disclose the nationality and identity of the troops but the British Ministry of Defense said two of the soldiers served in the Royal Air Force.
"The incident is currently under investigation but we can confirm that it was an accident and not the result of insurgent activity," the British Ministry of Defense said, adding that the helicopter was a UK Puma Mk 2.
Five other troops were injured in the crash.
Most of the troops involved in the Resolute Support Mission are with the U.S. military. Resolute Support troops are not supposed to actively engage in combat.