"It is clear that the threat of destabilization [in Crimea] by external forces still remains <…> they could play a nationalist card or they could use mistakes, blunders and ineffective actions by local authorities to funnel justified concerns of local residents into a destructive wave," Putin said at a meeting on security situation in Crimea.
According to the president, this issue is openly discussed in "certain capitals."
"They talk about the necessity of carrying out subversive activities, correspondent entities are formed, personnel is recruited and trained to carry out diversions, acts of sabotage to conduct radical propaganda," he stated.
Crimea split from Ukraine to rejoin Russia in March 2014 following a referendum in which over 96 percent of voters supported the move.
Shortly after Crimea's reunification, the Russian Federal Security Service (FSB) announced the arrest of Ukraine's Right Sector nationalist party members believed to have plotted terrorist acts in the Crimean cities of Yalta, Sevastopol and Simferopol.