Ukraine means to close a transit point connected to a huge natural gas pipeline, which transmits almost a third of the natural gas imports from Russia to Europe.
The news comes from Gas Transmission System Operator of Ukraine (GTSOU).
The TSO has requested that Russia turn off the gas along the Sokhranivka route, which runs through the breakaway republic of Luhansk.
Luhansk has for some time been controlled by Russian forces and pro-Russian separatists.
According to Chief Executive Officer of GTSOU Sergiy Makogon, Russia has begun redirecting natural gas to the two breakaway republics of Donetsk and Luhansk, which together make up the Donbas region.
Makagon presented no immediate evidence of natural gas having been redirected.
However, Russian state-owned gas company Gazprom, which has a monopoly on exports through natural gas pipelines, says that there are no practical options for rerouting natural gas flows in a western direction, as proposed by GTSOU.
The Ukrainian TSO proposes to redirect natural gas via the Sudzha pipeline, which runs through the Russian town of Sudzha before crossing the border to the Ukrainian city of Sumy.
According to US think tank Institute for Study of War, Sumy is under Ukrainian control.
Ukraine has requested that Russia shut off gas along Sokhranivka on the grounds that this is a force majeure situation.
However, Gazprom reports to have seen no evidence of a force majeure, informing that it still plans to meet commitments with European buyers.