A Ukrainian military plane flew within three to five km of flight MH17 just before the crash, the Russian Defence Ministry has claimed.
Moscow also denied supplying pro-Russian rebels with BUK missile systems.
It came after Ukraine’s Prime Minister said Vladimir Putin is “on the side of the devil” as he reiterated Kiev’s view that Russia had a clear role in shooting down the airliner.
Arseniy Yatsenyuk said the Malaysia Airlines plane carrying 298 people was probably brought down by a BUK-M1 missile launcher.
“This system could not be operated by drunk pro-Russian terrorists. There were professional people,” he told a news conference.
He also said Kiev is willing to hand over the probe into the atrocity to its Western partners.
In the Netherlands, Dutch King Willem-Alexander and Queen Máxima are meeting relatives of the 193 Dutch people who died on the plane.
The pair have been criticised for not attending memorial services for the victims on Sunday. Their aides are refusing to say what they were doing instead.
Earlier, the Russian President vowed to “do everything to ensure the security and safety” of experts investigating the disaster.
Mr Putin said “all people” in Ukraine are responsible for the tragedy.
“No one has the right to use this tragedy for any kind of vested interest in the political sense. Such incidents should unite people rather than separate them,” he said.
“We need to do everything to ensure the security and safety of the observers and the experts working at the crash site.”
However, Mr Yatsenyuk said: “I do not expect anything from the Russian government … Putin should understand that it’s enough already. This is not a conflict between Ukraine and Russia. It is an international conflict.”
He added: “Russia is on the dark side, on the side of the devil.”