Post-Soviet leaders will continue a two-day informal summit in southern Russian Wednesday, focusing on a common energy market and customs union as part of the five-member Eurasian Economic Community (Eurasec). The presidents of Kazakhstan, Kyrgyzstan, Tajikistan and Belarus joined Russian leader Vladimir Putin in Russia\'s Black Sea resort of Sochi Tuesday, along with the prime minister of Armenia, which is an observer in the organization. \"The agenda includes the formation of a customs union within the organization,\" a Kremlin source said earlier in the week. \"Strategy and tactics for the community\'s progress will be discussed in this context.\" Ukraine\'s prime minister, Viktor Yanukovych, is also attending the summit as part of his first foreign trip in his new capacity, which he assumed on August 4. Putin and Yanukovych are expected to focus on controversial issues of bilateral relations, including supplies of Russian natural gas to Ukraine. The Kremlin official also said the leaders would discuss formation of the common energy market as part of a Russian initiative to set up international centers offering nuclear fuel services announced by President Vladimir Putin at the Eurasec summit in St. Petersburg in January. \"We need to create a prototype of such global infrastructure that would enable all concerned parties to have equal access to nuclear energy. I would like to emphasize that non-proliferation requirements have to be reliably observed in the process,\" Putin said. The president said the UN\'s nuclear watchdog, the International Atomic Energy Agency, should oversee the centers. \"A system of IAEA-controlled international centers offering nuclear fuel services, including enrichment, without discrimination, should become a key element of the suggested infrastructure,\" he said then. The Kremlin source said the leaders would also discuss the preparation of documents establishing the legal basis for Uzbekistan\'s accession to Eurasec. The five members of Eurasec, set up in 2000, agreed in January to admit Uzbekistan to the organization, which also includes Moldova, Armenia and Ukraine as observers. (RIA Novosti)