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 (Ukrainian: Харківський пакт) or Kharkov Accords (Russian: Харьковские соглашения), 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 renewal option in exchange for a multiyear discounted contract to provide Ukraine with Russian natural gas.The agreement, signed on 21 April 2010 in Kharkiv, Ukraine, by Ukrainian President Viktor Yanukovych and Russian President Dmitry Medvedev and ratified by the parliaments of the two countries on 27 April 2010, aroused much controversy in Ukraine. The treaty was effectively a continuation of the lease provisions that were part of the 1997 Black Sea Fleet Partition Treaty between the two states. Shortly after the March 2014 annexation of Crimea by the Russian Federation, Russia unilaterally terminated the treaty on 31 March 2014.