The presence of Russia's Black Sea Fleet in the country has been a source of contention between the ex-Soviet neighbors. Under agreements signed in the 1990s, the Russian fleet will remain in Ukraine until 2017.
Viktor Yushchenko told the Russian media, "On this issue we will stick to the letter and the spirit of the law."
The two countries clashed earlier this year over the ownership of lighthouses at the naval base, and Ukraine's demand for a hike in the rent Russia pays. Some politicians called for a review of the original deal on the Black Sea Fleet.
Under a bilateral agreement signed by the Russian and Ukrainian leaders in 1997, the fleet is to remain in Sevastopol until 2017, at an annual rent of $93 million. But Ukrainian media have speculated that future deals on the base will be linked to the price Russia sets for natural gas supplied to Ukraine.
"There are core documents on the presence of Russia's Black Sea Fleet in the Crimea, which envision the presence of the fleet on the Crimean Peninsula until 2017," President Yushchenko said.
Ukraine's leadership, which has committed itself through a national unity pact to pursue integration with NATO and the European Union, earlier said it wants Russia to withdraw from the peninsula when the accord expires.
