Ukrainian President Petro Poroshenko has signed a decree, ending Russian-Ukrainian Friendship Treaty.
The decree has been published on the official presidential website on Monday.
"Treaty on Friendship, Cooperation, and Partnership between Ukraine and the Russian Federation" was signed between Russian and Ukraine in 1997, describing the two countries as "strategic allies".
The treaty states that Russian and Ukraine "shall respect each other's territorial integrity and reaffirm the inviolability of the borders existing between them".
In 2014, Russia annexed the Crimean Peninsula in violation of one of the principal articles of the treaty.
Source: Anadolu Agency