The US on Monday imposed further sanctions in connection with the Nord Stream 2 gas pipeline, Secretary of State Antony Blinken said, against Russia-linked company Transadria and its vessel, the Marin.
The State Department submitted a report to US Congress listing two vessels and an entity, Transadria, involved in the pipeline, Mr Blinken said. The vessel will be labelled as blocked property.
"With today’s action, the administration has now sanctioned eight persons and identified 17 of their vessels as blocked property … in connection with Nord Stream 2," the State Department said.
Washington opposes the $11 billion pipeline, which runs under the Baltic Sea to bypass Ukraine and carry gas from Russia's Arctic region to Germany.
Nord Stream 2 has also faced stiff opposition from some European states, which say it will make Europe too reliant on Russian gas.
But other European governments say the link is crucial to secure energy supplies, with gas prices surging in recent weeks and the threat of power cuts looming this winter.
The US administration of President Joe Biden has waived sanctions on the pipeline's operator and reached an agreement with Germany in July over the pipeline.
Germany agreed to take action if Russia uses energy as a weapon in its relations with Ukraine, but the pact did not provide criteria for how that would be judged.
Last week, Germany's energy regulator temporarily halted the certification process for the new pipeline, hampering the contentious project and driving up regional gas prices.
"Even as the administration continues to oppose the Nord Stream 2 pipeline, including via our sanctions, we continue to work with Germany and other allies and partners to reduce the risks posed by the pipeline to Ukraine and frontline Nato and EU countries, and to push back against harmful Russian activities, including in the energy sphere," Mr Blinken said.
Ukraine will lose revenue if the pipeline from Russia bypasses it. Kiev accuses Moscow of using energy as a weapon to threaten Europe's security.
Reuters contributed to this report