The United States is moving to tighten the sanctions regime against Russian energy projects to Europe, with Secretary of State Mike Pompeo lifting exemptions carved out for some companies involved in the Nord Stream 2 and Turk Stream pipelines.
The US has been focused on trying to stall the Nord Stream 2 pipeline to Germany and the move marks the latest step, even as it does not immediately lead to new sanctions.
Pompeo told reporters on Wednesday that this was a "clear warning" to companies who are participating in the projects that they may face sanctions under a 2017 law that is meant to deter Russia, known as CAATSA.
"Get out now, or risk the consequences," Pompeo said.
European companies, as well as Russia's Gazprom, are building the lines. Pompeo rejected Moscow's insistence the projects are purely commercial.
Frank Fannon, a State Department official, clarified that the US was broadening the criteria for the types of investments and entities that could violate sanctions. He said the US wanted to "enhance transatlantic energy security."
The US imposed sanctions on the Nord Stream 2 project last year - saying the pipeline would increase the European Union's dependence on Russian gas - which had directly targeted the construction of the underwater pipeline.
Some companies involved in the projects benefited from exemptions and were not subjected to sanctions.
The new warning comes as Europe has pushed ahead with the project, despite the US efforts to slow it down.
Nord Stream 2, to span the Baltic Sea from western Russia to northern Germany, is to double the capacity of the eponymous Nord Stream pipeline already in operation.
Turk Stream brings gas from southern Russia across the Black Sea to Turkey and from there to Europe. The new threat by Pompeo could affect an upcoming project for another line.
Senator Ted Cruz, a leading lawamker pushing for tougher action against Russia, applauded Pompeo but said he planned to enact new legislation in Congress to force the Trump administration to impose even more sanctions.
"Today's action again confirms that there is a unified bipartisan, bicameral, inter-branch consensus across the whole of the United States government to ensure Putin's pipeline never comes online," Cruz said.