Hungarian Prime Minister Viktor Orban said he wasn't an "expert" on the issue but added he felt the Nabucco natural gas pipeline was "in trouble," reports Bloomberg News.
Hungarian energy company Mol, in an e-mail statement to Bloomberg, didn't state its formal position on Nabucco but said there were "many uncertainties around the Nabucco project that would be hard to ignore."
Nabucco's $10.4 billion price tag and its lack of formal supplier agreements have made some investors nervous.
Orban said, during mid-April meetings with Russian natural gas company Gazprom, that Nabucco counterpart South Stream is a strategic interest to both countries.
Russia's contractual woes with gas transit nation Ukraine exposed vulnerabilities in conventional natural gas routes for European consumers. Europe gets about 20 percent of its natural gas from Europe and roughly 80 percent of that heads through Ukraine.
Orban had said, however, that Nabucco is "important" because of it would bring diversity to Europe. The pipeline could get sourced from natural gas fields in Azerbaijan, breaking Russia's grip on the energy sector.
The Nabucco pipeline consortium, which includes Mol, has said there were no indications the Hungarian side had walked away from the project.