In the first sign that the sanctions were beginning to bite, Swiss contractor Allseas suspended its Nord Stream 2 activities

Germany on Saturday accused the United States of interfering in its internal affairs, in an increasingly angry spat over Washington's decision to impose sanctions on companies involved with a major project to supply western Europe with Russian gas.

Moscow and the European Union also issued statements criticising the sanctions, a day after President Donald Trump signed off on asset freezes and visa restrictions on those involved in the Nord Stream 2 project.

US lawmakers are seeking to stymie what they regard as an increasing reliance on Russian energy in western Europe by targeting the project, which aims to double the amount of Russian natural gas reaching Germany via a pipeline under the Baltic Sea.

The sanctions target contractors working to lay pipes for Nord Stream 2 -- a 10-billion-euro ($11-billion) project expected to be completed in early 2020 -- and another Russian gas project, TurkStream.

Full details of the sanctions have not yet been released and US officials have 60 days to disclose the names of the companies and individuals concerned.

In the first sign that the sanctions were beginning to bite, Swiss contractor Allseas suspended its Nord Stream 2 activities while it awaited clarification from the US authorities.

However, Nord Stream 2 said in reaction to the statement from Allseas that it would continue to work until the pipeline was finished.

- 'Particularly incomprehensible' -

Although US Congress overwhelmingly backed the sanctions, there was criticism from some lawmakers of a move that in effect punishes NATO allies such as Germany.

The move brought angry reactions from Berlin, Moscow and Brussels on Saturday.

An EU spokesman said the bloc was opposed "as a matter of principle to the imposition of sanctions against European companies engaged in legal activities".

The German government reacted most forcefully, with Chancellor Angela Merkel's spokeswoman Ulrike Demmer saying Berlin rejected "these sorts of extra-territorial sanctions".

"They will hit German and European companies and constitute an interference in our internal affairs," she said.

Vice Chancellor and Finance Minister Olaf Scholz said the sanctions were an infringement of sovereignty.

However, he said there would not be a tit-for-tat reaction, telling German TV: "It is up to the companies involved in the construction of the pipeline to take the next decisions."

Russian foreign ministry spokeswoman Maria Zakharova accused the United States of pushing an ideology that hindered global trade, adding on her Facebook page: "Soon they will demand that we stop breathing."

But the United States is not the only nation to question the project -- Ukraine, Poland and some Baltic nations have also expressed doubts.

"Despite the involvement in the Nord Stream 2 project of companies from some EU countries, this pipeline has never been a European or EU project," said Polish Deputy Foreign Minister Pawel Jablonski, quoted by the PAP news agency.

"Instead, it remains an instrument for the realisation of Russian economic and, potentially, military policy."

Ukraine had worried that the new pipeline would cut it out of the gas supply business and allow Russia to ratchet up pressure.

And Prime Minister Oleksiy Honcharuk said on Twitter that he welcomed the sanctions against a "politically motivated" project.

US lawmakers had cited support of Kiev as part of their justification for imposing sanctions.

But Demmer said this rationale was "particularly incomprehensible" because Moscow and Kiev reached an agreement in principle last week that will regulate the transit of Russian gas to Ukraine from 2020.

More than 80 percent of the undersea pipeline has been completed for the project -- half-financed by Russia's state-owned Gazprom, with the other half paid for by five European companies.