Ukraine's acting Presidnet Oleksandr Turchynov signed the bill passed by Parliament, declaring Crimea an occupied territory.
The bill was passed by Ukrainian Parliament on April 15, with the aim of ensuring the rights of citizens in the "temporarily occupied territories of Crimea and Sevastopol", ITAR-TASS informed.
According to the bill, Crimean airspace and waters remain part of Ukraine and citizens are free to cross into and out of the autonomous region.
Crimeans voted in a referendum on March 16 to split from Ukraine and join the Russian Federation. The decision has not been recognized by the international community and the interim government in Kiev.