KIEV, June 6. /TASS/. Ukraine’s Foreign Ministry said on Monday it has referred a note of protest to the Russian Foreign Ministry over a visit by the speaker of the Russian parliament’s upper house, Valentina Matviyenko, to Crimea.

"The Ukrainian Foreign Ministry expresses protest over the stay of speaker of Russia’s Federation Council Valentina Matviyenko in Ukraine’s sovereign territory in its internationally recognized borders, which include the autonomous republic of Crimea and Sevastopol, on June 3-4 that was not agreed with the Ukrainian side," the press service of the Ukrainian foreign ministry said.

"Matviyenko’s stay in the autonomous republic of Crimea is a flagrant disregard of Ukraine’s state sovereignty by the Russian authorities," the press service said, adding that the ministry has referred a note of protest to the Russian foreign ministry.

Matviyenko visited Crimea at the end of the past week to take part in the opening ceremony of the Livadia international forum "The Russian World: Problems and Prospects."

The Republic of Crimea and Sevastopol, a city with a special status on the Crimean Peninsula, where most residents are Russians, refused to recognize the legitimacy of authorities brought to power amid riots during a coup in Ukraine in February 2014.

Crimea and Sevastopol adopted declarations of independence on March 11, 2014. They held a referendum on March 16, 2014, in which 96.77% of Crimeans and 95.6% of Sevastopol voters chose to secede from Ukraine and join the Russian Federation. Russian President Vladimir Putin signed the reunification deals March 18, 2014.