They were killed on Friday but the names of the victims will be withheld until 24 hours after their families have been notified.
The deaths bring the number of US service members killed in Afghanistan this year to four.
It comes amid negotiations between the US and Taliban insurgents to end the 17-year conflict in Afghanistan.
- Why Afghanistan is more dangerous than ever
The top US envoy seeking to broker peace in Afghanistan met the Taliban’s co-founder for the first time in February.
Despite the negotiations, the country is more dangerous than ever.
More civilians were killed last year in Afghanistan than at any time since records have been kept, with 3,804 civilians losing their lives.
At least six people were killed in three bomb explosions in the the capital, Kabul, on Thursday during Persian New Year celebrations. The attacks were claimed by the Islamic State group.
Thousands of Nato-led troops remain in Afghanistan supporting government efforts against the Taliban.
President Trump is reportedly considering withdrawing half of the 14,000 American troops currently serving, which make up the bulk of the force.