Russia said on Wednesday it will soon finalise its side of the route for the "Power of Siberia 2" pipeline, a huge project to deliver more natural gas to China.

Moscow plans to start building the pipeline next year, after its military offensive in Ukraine forced it to move away from the European market in favour of Asian buyers.

"It is in the final phase," Russia's deputy prime minister and top energy official Alexander Novak said in an interview with the Russian magazine Energy Policy.

The pipeline will run through southern Siberia near the city of Achinsk and turn east towards Krasnoyarsk and Irkutsk before reaching the Mongolian border, Novak said.

When China's Xi Jinping visited Moscow in March, President Vladimir Putin said "all agreements" between the two countries had been made for the pipeline.

Novak said during the Chinese leader's visit that Russian and Chinese companies would sign contracts on the pipeline "by the end of the year".

But the schedule for its completion remains unclear.

Russia currently exports its gas from northeast Siberia towards China through the Power of Siberia 1 pipeline, launched in 2019.