The controversial Kharkiv Pact (Russian Ukrainian Naval Base for Gas Treaty) is signed in Kharkiv, Ukraine, by Ukrainian president Viktor Yanukovych and Russian president Dmitry Medvedev; it was unilaterally terminated by Russia on March 31, 2014.

The Agreement between Ukraine and Russia on the Black Sea Fleet in Ukraine, widely referred to as the Kharkiv Pact or Kharkov Accords, was a treaty between Ukraine and Russia whereby the Russian lease on naval facilities in Crimea was extended beyond 2017 until 2042, with an additional five-year…