He stressed that the White house still does not recognize the legitimacy of the referendum in the Peninsula held on 16 March 2014.

"We remain deeply concerned about the situation in Russian-occupied Crimea, where the occupying "authorities" suppress dissent, and ethnic and religious minorities - in particular the Crimean Tatars and ethnic Ukrainians are facing serious persecution," reads the statement on the Department's website.

"We do not recognize the crossing of borders by force in the XXI century. Sanctions related to the Crimea will remain in force as long as there is an occupation," added Kirby.

According to the organizers of the referendum, 96,77% of Crimean residents voted two years ago for joining the region to Russia.

Resolution of the UN General Assembly on 27 March 2014, in which the referendum qualifies as unenforceable, was supported by 100 States. On the side of Russia was made by the 11 countries abstained from voting in 58 countries (including BRICS countries).

According to a survey by the American research centre Pew Research Center, in the spring of 2014, 82% of Ukrainians living in the West of the country, condemned the actions of Moscow and considered inadmissible the recognition of the exclusion of the Crimea.

In the East of Ukraine this was the position taken 41% (with 40% supporting the separation of Crimea).

In Crimea support the secession of the Peninsula from Ukraine were expressed by 88% (4% vs.).