US military deaths in the Afghan war have reached 2,000, a cold reminder of the human cost of an 11-year-old conflict that garners little public interest at home as the United States prepares to withdraw most of its combat forces by the end of 2014.

The toll has climbed steadily in recent months with a spate of attacks by Afghan army and police against American and NATO troops, and questions about whether allied countries will achieve their aim of helping the Afghan government and its forces stand on their own after most foreign troops depart in little more than two years.

A US official confirmed the latest death on Sunday, saying that an international service member killed in an apparent insider attack by Afghan forces in the east of the country late on Saturday was American. The official spoke on condition of anonymity because the nationality of those killed had not been formally released.