Moscow's mayor has made strong calls for the disputed ownership of a Russian naval base on Ukraine's Crimean peninsula to be transferred back to Russia.
"Russian citizen Yury Luzhkov has been barred from entering Ukraine, starting on May 12, because, despite warnings he continued to call for actions that threaten Ukraine's national interests and territorial integrity," Ukraine's Security Service said in a statement.
Russia's Black Sea Fleet currently uses a range of naval facilities in the Crimea under a 1997 agreement allowing Russia to lease the base from its ex-Soviet neighbor for $93 million per year until 2017, which is paid for by Moscow with Russian energy supplies.
There have been frequent disputes between Russia and Ukraine over the lease of the base.
"This issue remains unresolved. We will resolve it for the sake of our state interests, for the sake of the lawful right that Russia has to the naval base of Sevastopol," Yury Luzhkov said on Sunday during celebrations in Sevastopol to mark the Black Sea Fleet's 225th anniversary.
According to Luzhkov, Soviet leader Nikita Khrushchev gave the Crimea to Ukraine in 1954 as "a token of brotherly love," but under a 1948 decree Sevastopol was assigned special city status "under the governing central authorities," and, therefore, could not be included in the list of territories transferred to Ukraine.
"I do not want a split [between Russia and Ukraine over the base], I just want to speak the truth," Luzhkov said, ignoring previous warnings from Ukrainian authorities not to repeat his numerous calls for the base to be handed over to Russia.
The Crimea, now an autonomous region within Ukraine, is a predominantly Russian-speaking territory. Since the 1991 breakup of the Soviet Union, the Crimea has unsuccessfully sought independence from Ukraine. A 1994 referendum in the Crimea supported demands for a broader autonomy and closer links with Russia.
Last month, the head of the State Duma committee on CIS affairs, Alexei Ostrovsky, said that Russia could reclaim the Crimea if Ukraine was admitted to NATO. Media reported that then-president Vladimir Putin issued a similar threat at a closed-door speech to NATO leaders at the Bucharest summit earlier in April.