Sofia - Bulgarian Prime Minister Sergei Stanishev said on Friday that his country would restart a Soviet-era nuclear power reactor at Kozloduy, in the face of severe ongoing gas shortages due to the energy dispute between Ukraine and Russia.

Bulgarian news agency Focus reported that Stanishev said his government had decided to begin the 45-day technical preparation process to restart the reactor, because the country had still received no gas from its Russian supplier.

Earlier on Friday, Bulgarian President Georgi Parvanov called for a new European Union energy policy in the wake of the ongoing dispute.

Brussels/Moscow/Kiev/Berlin - Saturday's gas summit between Russia and Ukraine is the "last and best chance" for both sides to salvage their reputation as reliable suppliers, the European Union said Friday as it faced another freezing week with reserves running low.

Russia warned European leaders they must attend the Moscow summit if they cared to see gas flow renewed because bilateral talks would no longer suffices.

"Unfortunately, this issue has gotten beyond bilateral relation," Russian President Dmitry Medvedev was quoted by news agency Interfax as saying.

Ljubljana - Slovenia's prime minister on Friday told the head of Russian natural gas monopolist Gazprom that eastern European countries should not have to go without gas due to a trade dispute between Russia and Ukraine.

Neither Slovenia, or other European Union members should be held hostage to the unresolved issues between Russia and Ukraine, Prime Minister Borut Pahor told Gazprom chairman Alexei Miller during a meeting in Slovenia's capital.

Sofia - Bulgarian President Georgi Parvanov has called for a new EU energy policy in the wake of the ongoing gas dispute between Russia and Ukraine.

In a speech on national security Friday in Sofia, Parvanonv said that it was "important to build a dependable partnership" between the states of the Caspian littoral.

Parvanov added that the proposed Nabucco pipeline project, which would see gas distributed from the Caucasus without passing through Russian or Ukrainian territory, was not just about a physical project, but also about politics.

Berlin - The gas dispute between Russia and Ukraine demonstrates to the world the need to diversify energy supplies, British Prime Minister Gordon Brown said Thursday.

Events of recent weeks showed how a commercial dispute could impact across Europe, Brown told a news conference after talks with German Chancellor Angela Merkel in Berlin.

Merkel urged Russia and Ukraine to return to the negotiating table and resolve their differences so that gas supplies could be resumed as quickly as possible.

Moscow/Kiev  - Ukraine's government is divided by internal differences over entering new talks with Russia to end the gas delivery impasse, news reports said Thursday.

Prime Minister Yulia Tymoshenko was quoted as saying by the Interfax news agency that a new round of talks on resuming gas transit to the European Union was scheduled for Saturday in Moscow.

However, President Viktor Yushchenko on Wednesday evening rejected the Kremlin's invitation a crisis summit with all gas-importing countries on Saturday as not suitable.