KIEV, March 20 (RAPSI) – Ukraine's National Security and Defense Council has instructed the Foreign Ministry to introduce a visa regime with Russia, Secretary of the Council Andrei Paruby said at a briefing.

On Tuesday, leaders of the Autonomous Republic of Crimea and Russian President Vladimir Putin signed a treaty unifying Crimea with Russia. On Wednesday, Putin submitted the bills confirming Crimea's unification with Russia to the lower house of parliament.

Ukraine defined Russia's acts as annexation and handed a note of protest to Russian charge d'affairs in Kiev Andrei Vorobyov.

Crimea, a largely Russian-speaking republic within Ukraine, was part of Russia until it was gifted to Ukraine by Khrushchev in 1954. President Putin said in his address that the decision was made with evident violations of the constitutional norms prevailing at the time.

Putin signed a decree Monday recognizing Crimea as an independent state, following a referendum Sunday that saw voters overwhelmingly support secession from Ukraine and reunification with Russia.

Crimea's leadership has refused to recognize as legitimate the new government in Ukraine that came to power following the ouster of President Viktor Yanukovich last month.