BUNNIK, Netherlands (AP) — The Dutch-led team carrying out a criminal investigation into the downing of Malaysia Airlines Flight 17 over eastern Ukraine in July 2014 says it soon should determine the exact launch site of the missile that brought down the plane, killing all 298 people on board.

But Fred Westerbeke, the prosecutor leading the international probe, warned Monday that completing the investigation would take much longer. He declined to name a possible finishing date.

After briefing relatives of victims on the investigation, Westerbeke pledged to complete the investigation "as quickly as possible, if only because of the frustration among the families."

A Dutch civil investigation concluded that the plane was downed by a Soviet-designed Buk surface-to-air missile.