"Despite all our efforts we can't yet legally substantiate the presence of Russian regular army in Donbass," Tuka said in an interview to the Apostroph online media outlet.
On Monday, the National Security and Defense Council of Ukraine will hold a meeting, where reportedly the bill of Donbass' reintegration will be discussed.
Kiev has repeatedly accused Russia of interfering with the country's interior affairs, but Moscow has, in turn, denied all the allegations. The Russian Defense Ministry has repeatedly claimed it has not supplied any military equipment or ammunition to the self-proclaimed Donetsk People’s Republic (DPR) and Lugansk People’s Republic (LPR). Russian Foreign Ministry Sergei Lavrov also repeatedly pointed out that Kiev's allegations about Russian military presence in Donbass were unfounded, since nobody has submitted any evidence yet.