The international team carrying out a criminal investigation into the downing of Malaysia Airlines Flight 17 over Ukraine nearly two years ago says it will reveal details of the weapon used and the exact launch site "after the summer."

A Dutch civil investigation reported last year that a Soviet-designed Buk surface-to-air missile downed the Amsterdam to Kuala Lumpur flight on July 17, 2014, but it didn't say who fired it.

All 298 passengers and crew were killed as the jet disintegrated in midair and plummeted to the ground in conflict-torn eastern Ukraine.

On Friday, the Joint Investigation Team seeking to apportion blame said its probe is "at a very advanced state," but is still waiting on some forensic analysis and for information from Russia about Buk installations.