Berlin has accused Washington of interfering in German internal affairs, after Donald Trump signed off on US sanctions against companies building a Russian natural gas pipeline to Germany.

"The Federal Government rejects such extraterritorial sanctions," Ulrike Demmer, a spokeswoman, said in Berlin on Saturday.

“They affect German and European companies and constitute an interference in our domestic affairs."

The US is an outspoken opponent of the Nord Stream 2 pipeline, which will transport natural gas about 750 miles from Russia, through the Baltic Sea and into Germany.

The sanctions will hit any company working with Russia’s state-owned Gazprom to complete the project.

On Saturday, Switzerland-based Allseas, which operates ships laying sections of the undersea pipeline, said it was suspending work on the £8.5 billion project, which is well advanced.

Washington and Eastern European countries oppose the project because it will increase the EU’s heavy dependence on Russian gas imports.

The pipeline will double Russian energy imports into Germany and, the US fears, give the Kremlin leverage over the EU and its leading economy.