Russian state-controlled gas giant Gazprom is making the assumption that no more gas will flow to Europe via Ukraine after Dec. 31 in its internal planning for 2025, a person familiar with the plans said.

Kyiv has indicated it will not extend the transit deal, ending over 50 years of gas flows from Siberia to central Europe — a vital revenue stream for Russia since the Soviet era.

Russian gas exports to Europe through Ukraine have been stable on Monday despite a contractual row between Kremlin-owned Gazprom and Austria's OMV , which halted gas flows to the Vienna-based company this month.