MOSCOW (AFP) - When Russian President Vladimir Putin visits China this week, a much-debated plan to build a pipeline eastward from Russia's Siberian oil fields is likely to top the agenda.
Russia has hedged for years on a promise to build a pipeline to either China or Japan, its two energy-thirsty Asian neighbors, as it weighs economic benefits against diplomatic and ecological considerations.
A pipeline to China would run 2,400 kilometres (1,440 miles) from the Siberian city of Angarsk -- the easternmost point in Russia's massive oil pipeline network -- to China's Daqing over 1,700 kilometers of Russian territory.
A pipeline supplying Japan would cover 4,130 kilometers from the Siberian city of Taichet to the Russian port of Nakhodka.
Russian officials and oil executives have added to the confusion over which plan Moscow prefers by making conflicting promises to both countries over the past several years.
According to Vladimir Milov, Russia's former deputy energy minister, the Chinese route is economically viable, saying "there is enough oil to fill the pipeline" in the fields of central Siberia and in the Irkutsk and Tomsk regions.
Other factors, however, work against this route, such as the fact that the pipeline would only supply China, which could try to negotiate a lower price for the oil, Milov said.
Talks with China to develop the Kovykta gas field have shown what an unyielding negotiator Beijing can be -- it is offering 30 dollars for 1,000 cubic meters, much lower than the 75-dollar minimum profitable price, according to Milov.
Ecological worries also work against the Chinese route as Beijing refuses to have the pipeline run through Mongolia and demands it passes near Russia's Lake Baikal, a pristine region protected by the UNESCO as a World Heritage site.
Russia's failed promise in 2001 to supply China with 30 million tonnes of oil per year and its decision to bar Beijing from bidding for the Slavneft oil company two years ago soured relations and complicated negotiations, he said.
Financial difficulties of the oil giant Yukos, engaged in a year-long battle with the Russian state over payment of back taxes and a main backer of the route, has also undermined the Russo-Chinese pipeline project.
But the Japanese route has pros and cons of its own.
Besides Japan, it could supply oil to other countries in the region, including South Korea, and even, potentially, the west coast of the United States.
But this option could end up being much less profitable than a Chinese pipeline because it would require a lot of oil in order to make economic sense.