NATO's operation in Afghanistan says two U.S. military personnel have been killed while conducting an operation.
In a statement on March 22, the Resolute Support mission gave no further details and withheld the names of those killed.
"In accordance with U.S. Department of Defense policy, the name of the service members killed in action are being withheld until 24 hours after notification of next of kin is complete," NATO said.
Violence has persisted in Afghanistan even as Taliban militants have held negotiations with U.S. officials about a peace settlement.
The latest talks wrapped up earlier this month with both sides citing progress, but no agreement.
The Resolute Support mission includes 17,000 troops, with about half of them from the United States.
The deaths come a day after at least six people were killed by blasts in an Islamic State-claimed attack during Norouz celebrations in a Shi'ite neighborhood of the capital,Kabul.
The number of American casualties has fallen dramatically since the end of 2014 when Afghan forces took over from U.S.-led NATO combat troops to secure the country.
The latest deaths bring the number of U.S. military personnel deaths in Afghanistan to at least four this year, and a total of at least 65 U.S. military deaths since January 2015, according to U.S. government and NATO reports.
The conflict has taken a much larger toll on Afghan security forces and civilians.
Fighting continues across Afghanistan more than a week after the latest round of negotiations between the United States and the Taliban ended in Qatar, as Washington seeks an end to the nearly 18-year war.
The Afghan government has complained it is being left out of the talks, because of the Taliban's refusal to negotiate with what they consider "a U.S. puppet."