10 August 2016, 16:51 GMT
KIEV (Sputnik) — The Ukrainian General Staff has already denied the claims calling them a provocative act by Moscow.
"Ukraine decisively condemns terrorism in all its forms, and rejects any use of terrorism-related measures to stop the occupation of Crimea," Poroshenko said in a statement posted on his official website.
Russia's Federal Security Service (FSB) said earlier on Wednesday that it had eliminated a spy ring organized by the Ukrainian Defense Ministry in Crimea, detaining both Russian and Ukrainian nationals involved in preparing terrorist attacks on the peninsula.
Two Russian servicemen have been killed in preventing the attacks. Russian President Vladimir Putin accused Kiev of resorting to terrorism and warned that such actions would not be left unanswered.