KABUL, Afghanistan

At least two U.S. soldiers were killed in Afghanistan during an operation, an official statement said Friday.

The NATO-led Resolute Support mission said in accordance with U.S. Department of Defense policy, the name of the service members killed in action are being withheld until after the notification of next of kin.

No further details were made public as to where and how the incident happened.

There has been no claim of responsibility but Taliban spokesman Zabihullah Mujahed said in a Twitter post that "scores of enemy soldiers" were killed in Farah province bordering Iran in an ambush.

With the latest casualties, the number of U.S. soldiers killed in Afghanistan this year has reached four.

The incident comes as the two sides are engaged in landmark face-to-face talks in Doha, Qatar to end the longest American war of its history entering the 18th year in the war-ravaged country.