Moscow has gone on the offensive over accusations that pro-Russian separatists were responsible for the shooting down of Malaysia Airlines Flight MH17.
Russian authorities claim their radars detected a Ukrainian Air Force plane flying within five kilometres of the passenger plane.
It has called on Kyiv to explain, and also rejected claims that Moscow supplied the separatists with anti-aircraft missile systems.
“I would like to emphasise that the Russian Federation did not give local fighters the defence rocket system BUK or any other type of arms or military equipment,” said Andrei Kartopolov from the Russian Defence Ministry.
The US and other countries have joined Ukraine in pointing the finger at the pro-Russian separatists, claiming Moscow was also complicit in what happened.
President Putin earlier said Moscow would work to end the conflict in Ukraine, but said no one should use the plane tragedy to score political points.
Ukraine says it stands by its claims that the pro-Russian fighters received a BUK radar-guided missile system from Russia, most likely with a crew.