Germany and the US have warned they could target a key Russian gas pipeline if the country invades Ukraine.
A US state department spokesman said the Nord Stream 2 pipeline “will not move forward” if Russia were to attack.
The controversial energy project is designed to double gas flow and runs from Russia direct to Germany under the Baltic Sea.
It circumvents Ukraine, which relies on existing pipelines for income and is under threat from Russian forces.
Tens of thousands of Russian troops have massed on Ukraine’s borders in recent weeks, prompting fears of an invasion – despite repeated Russian denials of any plan to attack.
On Wednesday the US rejected Russia’s key demand to bar Ukraine from joining the Nato military alliance while offering Moscow a “serious diplomatic path forward”.
President Vladimir Putin is currently assessing the proposals, his spokesman said on Thursday.
