KIEV (AFP) -- Ukraine and Russia were braced for more pressure on their strained relations during talks here Tuesday over Moscow's Black Sea fleet stationed in Crimea.

"There is no doubt that the meeting will not be easy," Anatoly Kinah, Ukraine's national security council chief, said on the eve of the meeting of an intergovernmental subcommission on the fleet in the Ukrainian capital.

"Solving systematic problems in bilateral relations that have been accumulating for years is always very complicated," Kinah was quoted as saying in a statement. The Russian Foreign Ministry said in a separate statement that "the problems of the Black Sea fleet are an important part of Russo-Ukrainian relations and the fleet's stationing in Crimea" and that "the Russian side is ready for a constructive exchange of opinions with Ukrainian colleagues."

Observers expect the meeting to produce more discord between the bickering neighbors, following verbal salvos earlier this year over control of Crimean navigation sites and recent exchanges over the price that Moscow pays for the naval base.

The fleet dispute is the latest in a string of rows to sour relations between the two capitals over the past year, after President Viktor Yushchenko defeated a Moscow-backed candidate in the "orange revolution" election campaign and assumed power in ex-Soviet Ukraine with a vow to steer it toward the West.

One of the main sticking points is Ukraine's insistence on hiking the price that Moscow pays to lease land and property for the fleet headquarters, to bring it in line with what other governments pay to house military bases abroad.

Russia says the price, just under 100 million dollars (83 million euros) annually, cannot be changed as it was set in a 20-year lease agreement that the two nations signed after six years of negotiations in 1997.

"The base agreement ... clearly states that the annual rent ... until 2017 will be just over 97 million dollars," Russian Defense Minister Sergei Ivanov said last week.

But Ukraine says that, following Russia's demand earlier this year on doing away with contracts under which Moscow provided Kiev with subsidized gas, the same had to be done with the rent for the Black Sea fleet base.

"The call by Russia's leadership, and in part by President (Vladimir) Putin, that our relations should be based on international standards quite suits Ukraine," Oleg Rybachuk, presidential chief of staff, said last week. "When it came to the price for gas, Ukrainian authorities took a step so that there would be market relations between us," he said. Increasing the rent for the Black Sea fleet "is yet another step to direct relations with Russia toward international standards."

Last week, Kinah estimated that a new "market" rent for the Crimean base could be 1.8 billion dollars.

For its part, the Russian side is likely to focus on another thorny issue during Tuesday's talks -- which side has the right to operate hydrography sites in Crimea.

In January, Russia boosted security around disputed sites in Crimea after what it called a "seizure" by Kiev of a Yalta lighthouse, which had previously been under the fleet's control.

Kiev said that it simply regained jurisdiction over an installation to which it had a legal right and in turn branded the boosting of Russian personnel at other navigation-related sites "unlawful." Russia's Black Sea fleet has been based in Crimea ever since its founding in the late 18th century under Catherine the Great, after Russia took the peninsula from Turkey.

Crimea was part of the Russian Federation until 1954, when Soviet leader Nikita Krushchev "gave" it to Ukraine -- a move that had no practical consequences during the Soviet era but that laid the foundation for a hot dispute after Ukraine gained its independence following the USSR breakup in 1991.

A press conference on the results of Tuesday's meeting in Kiev was due to be held at 06:00 P.M. (1600 GMT) yesterday.