"Romania can afford to wait, unlike other countries it has proved in the last winter it could handle the crisis ... but it cannot wait long," Reuters quoted Deputy Economy Minister Tudor Serban telling an energy seminar.

"If Nabucco does not materialise ... it is clear that (Romania) will enter talks for a project, I don't want to say which one now."

The Nabucco pipeline has gained impetus following the gas price row between Russia and transit country Ukraine in January, which left many European countries without gas for two weeks.

But funding, the sourcing of natural gas and disagreement between consortium members have weighed on the project, which has had to push back some of its target dates, a Reuters report said.

The pipeline is expected to start pumping gas in 2014 if an agreement on the €7.9 billion ($11 billion) project can be reached, as expected, in June.

But the agreement hinges on whether Turkey drops a demand to keep 15% of the gas for resale.

Meanwhile, Russia is struggling to push ahead with the South Stream pipeline, due to start in 2015.

Nabucco shareholders are Austria's OMV, Hungary's MOL, Romania's Transgaz, Bulgaria's Bulgargaz, Turkey's Botas and Germany's RWE.

Prime Minister Emil Boc said today that while Nabucco remains a priority, Romania will be flexible over joining other projects, without specifically pointing to South Stream.

"Romania has the strategic advantage of holding an important part in any one of them (European projects), which is why Romania will have a flexible policy, being able to participate in other European projects," Boc said.

Earlier this week, Romanian President Traian Basescu said Russia and the European Union must increase co-operation on major issues despite distrust fuelled by Russia's military action in Georgia and controversy over gas supplies.

Published: 28 May 2009 14:43 GMT  | Last updated: 28 May 2009 19:34 GMT