The one-day gathering was the first of three planned international conferences ahead of a May 1 deadline for the final withdrawal of U.S. and NATO troops from the country.
Meanwhile, the U.S. military announced a sudden visit to the Mideast by long-range, nuclear-capable B-52H bombers, underlining America's continuing presence in the region.
U.S. peace envoy Zalmay Khalilzad on Saturday held the first official talks with Afghanistan’s Taliban since President Donald Trump declared a near-certain peace deal with the insurgents dead in September.