China and Russia have inked a long-awaited gas deal in Shanghai worth over 400 billion US dollars, ending a decade of natural gas supply talks between the two countries.Two documents and a memorandum were signed at a ceremony attended by Chinese President Xi Jinping and Russian President Vladimir Putin.

Chinese President Xi Jinping (2nd R) and Russian President Vladimir Putin (2nd L) attend the signing of the China and Russia Purchase and Sales Contract on East Route Gas Project and a memorandum in Shanghai, May 21, 2014.?

According to a bulletin on the China National Petroleum Corporation's website, the contract will come into effect in 2018. And it will see the east route pipeline provide China with 38 billion cubic meters of natural gas a year. The deal comes one day after the two leaders issued a joint statement, saying the two countries would "establish a comprehensive energy cooperation partnership."

The visiting Russian President also said on Tuesday that "significant progress" had been made over prices.