MOSCOW, MAY 29 -- Lithuanian Prime Minister Kazimiera Prunskiene told Moscow today that its economic embargo against the rebel Baltic republic would force the shutdown of a nuclear-power station supplying electricity to a key Soviet military region.

The region of Kaliningrad, accessible from the Soviet Union only through Lithuania, houses the headquarters of the Soviet Baltic Fleet and several large military bases.

In a telegram to Soviet President Mikhail Gorbachev and Prime Minister Nikolai Ryzhkov, Prunskiene said lack of fuel caused by the embargo meant that a power station linked to a nuclear power plant at Ignalina would close.

"The situation at the . . . power station could lead to an accident at the nuclear-power station. It will therefore be necessary to halt the operation of the nuclear-power station. This would lead to a disruption in electricity supplies in both Lithuania and the Kaliningrad region," said Prunskiene's telegram, read by a Radio Vilnius journalist.

Moscow imposed its economic sanctions on Lithuania to force the republic to suspend its March 11 declaration of immediate independence, something Vilnius refuses to do.

Boris Yeltsin, the populist politician elected president of the Russian republic today, said he is prepared to open negotiations with Lithuania and the other two separatist Baltic republics, Latvia and Estonia, on establishing direct economic links.

Lithuanian President Vytautas Landsbergis sent Yeltsin a telegram congratulating him on his election and said he hopes the way is now open for cooperation between Lithuania and Russia, Radio Vilnius reported.

Lithuanian attempts to set up direct trading links with cities in the Russian republic to swap meat for oil have been frustrated by the Kremlin, which banned freight trains from carrying virtually all goods into the Baltic republic.

A Lithuanian government statement said the republic is in a critical economic position. All the republic's oil-fired power stations have effectively closed down and 40,000 people are out of work, it said.

In Riga, capital of Latvia, the foreign ministers of Lithuania, Estonia and Latvia said they would not recognize any agreements on the Baltic crisis reached by Gorbachev and President Bush at their Washington summit starting Wednesday.

"The president of the Soviet Union has no legal authority to represent {the Baltic republics} at the upcoming summit. . . . Any eventual agreement signed there will not be binding upon the Baltic states," the statement said.

All three have declared independence -- Estonia and Latvia by slower means -- and denounced the Nazi-Soviet agreement that led to their forcible incorporation into the Soviet Union in 1940.