Ukrainian Security Service (SBU) chief Vasyl Hrytsak showed the video at a November 22 briefing in Kyiv, in an apparent bid to bolster Ukraine's claim that the men were apprehended after crossing into mainland Ukraine at a checkpoint near the Russian-controlled Crimean Peninsula.
Russian authorities arrested a number of Ukrainians in Crimea earlier this month and accused them of plotting sabotage against Russia, the BBC noted. Kiev said the men were detained in Ukraine.
The men allegedly crossed the border from contested Crimea, former Ukrainian territory annexed in 2014 by Russian Federation, and were then detained by Ukrainian authorities.
Terming the detention as "illegal", the Russian defence ministry said in a statement that "psychological and physical pressure" could be applied on them for forceful confessions.
The Russian defence ministry accused the Ukrainian security services of "fabricating" criminal charges against the two soldiers "for crimes allegedly committed against Ukraine".
According to journalist Anton Naumlyuk, the detainees are former soldiers of the Marine Aviation Brigade of the Ukrainian Navy in Novofedorovka (Crimea) Alexander Baranov and Maxim Odintsov.
Foreign Minister Sergei Lavrov called the men's capture "an unlawful act of provocation carried out by Ukrainian special services towards Russian citizens on Russian soil", quoted by TASS state news agency.
Amid Ukraine's continuing battle with Russian-backed separatists in eastern provinces, rights groups say both sides often abduct people to use as "currency" in prisoner exchanges, with military and intelligence staff of particular value.