Hungarian Prime Minister Viktor Orban welcomed progress on Russia's South Stream gas pipeline on Wednesday after meeting with the head of Gazprom.   "The situation in Ukraine confirms that the South Stream project has become a key question in Europe's gas supply," Orban's office said in a statement after the prime minister met in Budapest with Alexei Miller, head of Russian gas giant Gazprom. The statement did not elaborate on the reasons for Miller's visit but said the two men discussed Austria's recent decision to also get involved in South Stream. The pipeline will bring Russian gas through southern Europe, bypassing Ukraine. Europe had long discussed a rival project, Nabucco, bringing gas from Central Asia in order to wean itself off Russian gas, but the project fell apart in 2013 after years of stalemate.