The Russia–Ukraine border is the de jure international boundary between Russia and Ukraine. Over land, the border spans five Russian oblasts and five Ukrainian oblasts. Due to the ongoing Russo-Ukrainian War, which began in early 2014, the de facto border between Russia and Ukraine is different from the legal border recognized by the United Nations. As of 2024, Russia is militarily occupying a significant portion of Ukraine, and Ukraine is militarily occupying a very small portion of Russia.
According to a 2016 statement by Viktor Nazarenko, the head of the State Border Guard Service of Ukraine, the Ukrainian government did not have control over 409.3 kilometres (254.3 mi) of the international border with Russia. This stretch of land was formerly controlled by pro-Russian separatists under the Donetsk People's Republic and the Luhansk People's Republic (see War in Donbas), both of which were annexed by Russia in September 2022, seven months after the beginning of the ongoing Russian invasion of Ukraine. Ukraine has also not had authority over the Kerch Strait since 2014, when Russia annexed Crimea; the Ukrainian administration was pushed out of Crimea and Russian checkpoints were set up at the boundary with Kherson Oblast.
