One key country is holding up a natural-gas pipeline that would deepen ties between Russia and China

• Mongolia won't fund the Siberia-2 pipeline for the next four years, Radio Free Europe reports.
• The natural gas pipeline is an ambitious project to deepen trade between Russia and China.
• The pipeline already hit a snag as Moscow and Beijing face disagreements.

Plans for an ambitious natural-gas pipeline between Russia and China have hit a hitch, caused by a completely separate country: Mongolia.

According to Radio Free Europe , Mongolia's government did not include funding for the Power of Siberia-2 pipeline in its spending plans for the next four years. The country serves as a buffer state between both Russia and China, and its engagement would be necessary for the project's realization.

This fresh snag adds complications to an already uncertain mega-project.

Russian energy giant Gazprom started design and survey work on the pipeline in 2022 , projecting that it could deliver 1.8 trillion cubic feet of Russian natural gas to China each year

This would make the Siberia-2 pipeline Gazprom's biggest deal with Beijing, and could provide a much-needed solution to Western sanctions. After Russia invaded Ukraine the same year, energy restrictions on Moscow have crippled its gas trade.

Research commissioned by the firm found that Gazprom is unlikely to recover gas sales lost to the Ukraine war for at least a decade, placing a greater need on Siberia-2's deployment.

But Chinese counterparts face much less pressure, given that the country does not need more gas before the mid-2030s , energy experts have said. For this reason, pipeline negotiations have stalled between Beijing and Moscow, given price and supply level disputes.

According to Radio Free Europe, plans for the pipeline also contradict China's increasing shift towards green energy.

Moreover, the Siberia-2 project isn't China's only option: President Xi Jinping has also signaled support for the Line D pipeline, deepening ties with Turkmenistan.

Expanded access to Eastern markets has proven to be a lifeline for Russia as the West has increasingly shunned the Kremlin. China has been front and center in this transition, with bilateral trade ballooning to a record $240 billion last year.

With Moscow highly dependent on its relationship with Beijing, some experts have characterized it as an emerging vassal to China .