A total of 30 U.S. special operation troops and seven Afghanistan commandos were killed when the helicopter went down Saturday.
The helicopter that crashed was a twin-rotor Chinook, said an official at NATO headquarters in Brussels.
Authorities said the Chinook had just completed an operation against Taliban insurgents in the province of Wardak late Friday. The Taliban has claimed responsibility, saying its fighters brought the helicopter down with rocket fire.
None of the SEALs that were killed are believed to be the ones who killed bin Laden.
An American official said the incident marks the highest number of casualties recorded in a single incident since the Afghan war began in 2001.
NATO confirmed the overnight crash took place, but it said it was still investigating the cause and conducting a recovery operation at the site. It did not release details or casualty figures.
A senior U.S. administration official in Washington said the chopper was apparently shot down by insurgents. The official spoke on condition of anonymity because the crash is still being investigated.
"Their deaths are a reminder of the extraordinary sacrifices made by the men and women of our military and their families," said President Barack Obama in a statement.
With its steep mountain ranges, providing shelter for militants armed with rocket-propelled grenade launchers, eastern Afghanistan is hazardous terrain for military aircraft. Large, slow-moving air transport carriers like the CH-47 Chinook are particularly vulnerable, often forced to ease their way through sheer valleys where insurgents can achieve more level lines of fire from mountainsides.
The crash took place in the Sayd Abad district of Wardak province, said a provincial government spokesman, Shahidullah Shahid. The volatile region borders the province of Kabul where the Afghan capital is located and is known for its strong Taliban presence.
There have been at least 17 coalition and Afghan aircraft crashes in Afghanistan this year. Most of those crashes were due to pilot errors, weather conditions or mechanical failures. However, the coalition confirmed that at least one CH-47H Chinook helicopter was hit by a rocket propelled grenade in July 25. Two coalition crew members were injured in that attack.
The Associated Press contributed to this report.
