Turkey and four European countries have signed a landmark deal aimed at reducing Europe's dependence on Russian natural gas. The prime ministers of Turkey, Bulgaria, Austria, Romania and Hungary met in Ankara Monday to approve the deal, which envisions a gas pipeline stretching from the Caspian Sea region to Western Europe. But, even though an agreement has been reached troubles still lie ahead for the pipeline

The signing of the agreement to build the 3,300 kilometer gas pipeline followed seven years of tough negotiations. The pipeline will run from energy-rich Azerbaijan through Turkey to Bulgaria and Romania, ending in Austria.

Speaking at the signing ceremony, the head of the EU commission Jose Manuel Barroso said the pipeline was of historic importance.

"The Nabucco pipeline is of crucial importance for Europe's and Turkey's energy security," said Jose Manuel Barroso. "It ensures diversification of sources and routes, and brings together a reliable customer market with reliable suppliers with a reliable transit route."  

The Nabucco pipeline is seen as a rival to the Moscow-backed South Stream pipeline, which is to route Central Asian gas through Russia, Ukraine and the Balkans to Italy.

Doubts about the reliability of Russia and the Ukraine to provide gas resurfaced in January when a pricing dispute led to a cut-off of Russian supplies and severe energy shortages in Western Europe.

Among the hardest hit was last winter was Bulgaria. Bulgarian Prime Minister Sergey Stanishev stressed the particular importance of the pipeline to his country.

"To the Bulgarian government and the Bulgarian citizens, who were caught in the most unpleasant experience during the gas crisis in January this year, today's signing ceremony is a strong signing message both politically and economically," said Sergey Stanishev."

Hungary was also hit hard by last January's disruption. Hungarian Prime Minister Gordon Bajnai sees the pipeline as symbolic of a new wider cooperation.

"The way out of this crisis for all our countries lies by not turning inwards, but to the opposite by the greater levels of cooperation, coordination and integration," he said. "These are the buzz words for managing this crisis."

Europe's efforts to diversify its energy supplies is seen as not only an economic but political opportunity by Ankara. Turkey which neighbors energy rich countries of the near and Middle East is positioning itself as Europe's new energy bridge. Turkish Prime Minister Recep Tayyip Erdogan saw the agreement as having a far wider significance than just a gas pipeline.

'We are taking an important step for our countries, friendship and peace, and the welfare of upcoming generations, Mr. Erdogan says. "The Nabucco project will lay the groundwork for further improvement of Turkey's relations with the EU in energy."

Ankara's sees the growing importance of Turkey in helping Europe meet its energy needs as enhancing its credentials for EU membership.   But questions remain over the sustainability of the Nabucco pipeline.

According to analysts, Moscow is not pleased with efforts to weaken its grip on supplying energy to Europe. As a result, it is currently planning to build two new pipelines to serve the European market. Analysts says Russia is also working hard to buy up gas that could potentially supply Nabucco. Earlier this month it signed an agreement with Azerbaijan to buy its gas.

This would not be good news for Nabucco says international relations expert Soli Ozel of Bilgi University.

"Without Azerbaijan you can't really start it because the Iranian gas is nowhere to be seen  for the moment," said Soli Ozel. "Because Iran's relations with the West is not the best. Therefore if you going to do anything about Nabucco and start the project you have to be able to rely on Azeri gas."

But supporters of the project say Azerbaijan has enough gas to supply both Russia and Nabucco customers.

Supporters believe that once Nabucco is built it will draw in supplies from Egypt, Iran, Iraq and Turkmenistan if there is not enough from Azerbaijan.  But they say even the most optimistic supporters of Nabucco admit, in spite of the signing of the agreement , many many problems still need to be resolved.