For the first time on Monday, China began receiving massive supplies of natural gas from Siberia over the new "Power of Siberia pipeline" whose construction was only made possible because China is its only customer.

The 8,100 kilometer-long (5,000 miles) pipline starts at the Chayanda field in Yakutia in Eastern Siberia and extends southwards to end at the Heihe-Shanghai pipeline in China. It joins a 3,000 km (1,864 miles) section in Russia with a 5,111 km (3,176 miles) stretch in China terminating in Shanghai.

To be operated by Russia's state-owned company Gazprom, the Power of Siberia pipeline will deliver 38 billion cubic meters of natural gas to China annually by 2024. China will import 5 billion cubic meters of natural gas in 2020, and increase this amount to 38 billion cubic meters annually starting in 2024.

On May 21, 2014, Russia and China signed a 30-year natural gas deal worth $400 billion. It was this deal with China that made the project feasible. Construction began on Sept. 1, 2014 in Yakutsk and was witnessed by Putin and Chinese deputy prime minister Zhang Gaoli. Construction of the connecting pipeline in China started in June 2015.

The inauguration of this fantastic engineering achievement built to withstand intense Arctic cold was watched on video by president Xi Jinping and Russian president Vladimir Putin. Both leaders congratulated each other online after opening the pipeline via a video link.

"China and Russia are at a crucial stage in their national development, and our relations are entering a new phase, as well," according to Xi.

"That step brings the Russian-Chinese strategic partnership in the energy sector to a whole new level," said Putin in a statement to TASS, the state-owned news agency.

TASS confirmed natural gas started flowing through the pipeline on Monday. It also said gas deliveries will be increased incrementally over the coming years.

"Gas is flowing to the gas transmission system of the People's Republic of China," said Gazprom CEO Alexei Miller.

Various Chinese state-owned media outlets on Tuesday lavished praise on the pipeline deal, saying China now has access to a larger amount of "clean energy" that will greatly limit the country's use of polluting coal to produce most of its electricity. Nnatural gas is expected to provide 15% of China's energy mix by 2030, said the state-owned Xinhua news agency.

Western experts estimate total sales through the pipeline will represent nearly 10% of China's entire gas supply by 2022.