China and Russia's energy giants signed a framework agreement on Thursday on the Russian gas supply to China, making a leap forward in the decadelong gas negotiations.

The agreement to export gas to China through the eastern pipeline was signed between China National Petroleum Corp and Russia's Gazprom in the Russian city of St. Petersburg.

President Xi Jinping, who is there to attend the Group of 20 meeting, witnessed the signing ceremony with his Russian counterpart, Vladimir Putin, after meeting together.