Ukraine on Sunday called Russian Prime Minister Dmitry Medvedev's surprise visit to annexed Crimea a "deliberate provocation" aimed at destabilising the country on election day.

"A visit by the Russian prime minister to occupied Ukraine on the day of the presidential election in Ukraine is particular impudence and a deliberate provocation aimed at destabilising the situation in Ukraine," the foreign ministry said in a statement issued moments after Medvedev's arrival in Ukraine's annexed Black Sea peninsula.