Russian–Ukrainian Friendship Treaty
An agreement between Ukraine and Russia, signed in 1997, which fixed the principle of strategic partnership, the recognition of the inviolability of existing borders, and respect for territorial integrity and mutual commitment not to use its territory to harm the security of each other. The treaty prevents Ukraine and Russia from invading one another's country respectively, and declaring war. Ukraine announced its intention not to renew the treaty in September 2018. Russia–Ukraine relations have deteriorated since the 2014 Russian annexation of Crimea and Russian support for separatist forces in the war in Ukraine's Donbass region. In response, Ukrainian President Petro Poroshenko signed a decree not to extend the treaty.