The US has imposed sanctions on 13 vessels for their involvement in the construction of the Nord Stream 2 natural gas pipeline, despite exempting the project's developer.

Washington has long stated the pipeline shipping Russian gas to Germany via the Baltic Sea would threaten Europe’s energy security.

On its website, the Treasury Department said US entities are prohibited from dealing with the 27,200-bhp Vladislav Strizhov and Yury Topchev (both built 2006), two anchor handling tug supply vessels linked to Russia’s Sovfracht-Sovmortrans Group.

Separately, US companies are banned from providing goods and services to 10 offshore support and salvage vessels owned by Marine Rescue Service (MRS), a Russian state-run company.

These are the 2,990-bhp Kapitan Beklemishev (built 1985), 3,200-dwt Artemis Offshore (built 2018), 4,019-bhp Murman (built 2015), 7,070-bhp Bakhtemir (built 2019), 8,300-bhp Spasatel Karev (built 2012), 14,400-bhp Umka (built 1998), 16,800-bhp Narval (built 1997) and Sivuch (built 1998), 21,400-bhp Finval (built 2003), and 66-loa Baltiyskiy Issledovatel (built 2013).

The 29,500-gt pipe laying ship Akademik Cherskiy (built 2015), which is linked to the Amara Heat and Energy Property Fund, faces the same restriction.

Washington is also prohibiting US companies from trading with MRS if the transactions are related to the Nord Stream 2.

All the vessels are flagged in Russia. The sanctions are believed to be largely symbolic as Washington has announced it would waive the sanctions on the pipeline developer, backed by Russian state-owned Gazprom, and its chief executive Matthias Warnig.

“I have determined that it is in the national interest of the US to waive the application of sanctions,” US secretary of state Antony Blinken said in a recent statement.

“We will continue to oppose the completion of this project, which would weaken European energy security. … Our opposition to the Nord Stream 2 pipeline is unwavering.”

Previously, the sanctions had stopped non-Russian vessels from working on the 55bn-cbm pipeline.

Observers said the US’ waiver aims at appeasing some European allies, especially Germany, where Chancellor Angela Merkel is a staunch supporter of Nord Stream 2.

The 1,224-km pipeline is reportedly 95% complete, with the remaining section in Danish and German waters.

The Akademik Chersky and the 41,000-gt Fortuna (built 2010) recently began pipe laying to complete the project.