US officials have conducted one-on-one video conferences with European contractors to "point out far-reaching consequences" of their continued participation in the project, the German newspaper reported on Saturday.
The sources say that up to 12 representatives from the Departments of State, Treasury, and Energy took part in the talks. The US officials "in a friendly tone have made it very clear that they want to prevent completion of the gas pipeline’s construction".
"I believe that the threats are very, very serious", one of Die Welt's sources said.
The news comes after the US Senate on Thursday passed its version of the defence spending bill for the fiscal year 2021, which includes pipeline sanctions.
In December, Nord Stream 2 sanctions, as part of the US’ 2020 National Defence Authorisation Act, forced Swiss pipelay company Allseas to quit the project with just 100 miles of the pipeline left to put down. Russia is now finishing the pipeline on its own.