Kabul, Sept. 5 -- A Taliban suicide car bombing in Kabul on Thursday killed a U.S. service member, a Romanian soldier and at least 10 Afghan civilians in a busy diplomatic area that includes the U.S. Embassy - the second such attack this week underscoring Afghan government warnings that a preliminary U.S.-Taliban deal on ending America's longest war was moving dangerously quickly.

"Peace with a group that is still killing innocent people is meaningless," Afghan President Ashraf Ghani said in a statement.

A NATO Resolute Support mission statement said the two service members were "killed in action," without providing details or releasing their names pending notification of their families.

The American soldier was the fourth U.S. service...