Russian President Vladimir Putin said he has not thought about Russian journalist Kirill Vyshinsky's possible exchange for Ukrainian citizen Oleh Sentsov.

Vyshinsky has been arrested in Ukraine on high treason charges, and Sentsov is serving a lengthy prison sentence for terrorism in Russia.

"These are absolutely different and incomparable things, and therefore we haven't thought about it yet. But we've thought that common sense should prevail in Ukraine," Putin said during a Q&A session in Moscow on Thursday, when asked whether Vyshinsky could be exchanged for Sentsov.

Putin said he hoped Vyshinsky would be freed. "I hope we will secure the Russian journalist's liberation, including under pressure from international organizations, on which the Ukrainian administration depends today this or that way," Putin said.

Comparing the cases of Vyshinsky and Sentsov, Putin said the journalist had been "detained for his direct professional activity, for performing his journalistic duties."

"This is an absolutely unprecedented and unacceptable policy that the current Ukrainian rulers are pursuing today. It should draw a proper reaction from the international community, international human rights organizations," he said.

In commenting on Sentsov's case, Putin said he had been detained in Crimea "not for journalistic activities but for preparing a terrorist attack, preparing an explosion, which could have harmed particular people."