Russian natural gas will start flowing to China in 2019 as planned but construction of the pipeline carrying it will not be fully completed until 2022, a Gazprom spokesman told Reuters on Monday. The state-run gas producer said last week the huge Power of Siberia pipeline to carry gas from new East Siberian fields to China would not be completed until 2022, three years later than originally projected, but did not give details about gas deliveries.

Three sources with direct knowledge of the Gazprom's plans had told Reuters that Russia might postpone completion of the Power of Siberia pipeline until it built another route from existing fields.

"The gas will start flowing to China in 2019. The pipeline will be fully completed in 2022 when all the pumping stations will be built. Its capacity will be gradually increased until it reaches its peak," Gazprom spokesman Sergei Kupriyanov said.

Russian President Vladimir Putin oversaw the start of the Power of Siberia construction in September in the Far Eastern Republic of Yakutia. He pays close attention to the energy projects as oil and gas sales account for a half of state budget's revenues.