Russian President Vladimir Putin signed a treaty Tuesday to officially annex the Crimean region of Ukraine to the Russian Federation, CNN reports.
The treaty comes two days after a referendum in which Crimean citizens voted overwhelmingly to join Russia. Both the United States and European Union have said that the referendum and Russia’s annexation of the region are violations of Ukraine’s sovereignty and against international law.
The treaty must still be ratified by the Russian parliament, and it will require a change to the Russian constitution, which explicitly names the states that are members of the Russian Federation.
The document also states that all residents of Crimea will become Russian citizens, though there will be a short time for those who wish to leave to do so.