The US suspects that these parties are supported by Russia which allegedly seeks to undermine NATO, stop the deployment of US missiles and revoke punitive sanctions against Russia imposed after Crimea's secession from Ukraine, German newspaper Deutsche Wirtschafts Nachrichten (DWN) wrote, referring to the British Telegraph.
"It really is a new Cold War out there. Right across the EU we are seeing alarming evidence of Russian efforts to unpick the fabric of European unity on a whole range of vital strategic issues," an anonymous source told the Telegraph.
The American initiative occurred after Marine Le Pen's French party the National Front received a nine million-euro loan from a Russian bank in 2014.
If the US comes to the "conclusion" that NATO is in danger, US authorities will act "in the interests of national security" and impose sanctions against the parties involved.
The newspaper referred to Michael Maier who described the consequences of such sanctions in his new book:
"The sanctions are a part of a global war in which the United States takes advantage of the role of the dollar as a world currency. Banks might be prohibited to make transactions with such parties. They could be banned from entry in the United States, while the assets of the parties or individuals collaborating with them could be frozen," Maier wrote.