"It’s still under investigation whether these are parts of a Buk missile system or not. So it’s too early to draw any conclusion," JIT spokesman Wim de Bruin told RT in an interview.
Media reports suggested that the debris, secured during a recovery mission, belonged to a Russian-made missile.
In a previous statement, the JIT said it was investigating the origin of the discovered parts to shed light on the possible cause of the MH17 crash, but said the direct connection between the parts and the crash has not yet been established.
The Amsterdam-Kuala Lumpur flight MH17 was brought down on July 17, 2014 over the Donetsk countryside, killing all 298 people on board.
Ukrainian government forces and independence militias accuse each other of shooting down the Boeing 777 aircraft.
A final Dutch Safety Board report is due in October. Its preliminary findings said the passenger jet broke up in mid-air after being hit by high-energy objects.
In June, Russian arms manufacturer Almaz-Antey published the results of its inquiry into the crash, showing that flight MH17 was downed by a guided missile launched by a Buk-M1 system. The particular missile has not been produced in Russia since 1999, but remains in service in the Ukrainian Army, according to the manufacturer.