US Ambassador Richard Grenell, dubbed by some German media outlets as “Trump terrier”, has prompted outrage among some in Germany by sending out letters to European companies, outlining the “reputational costs and sanctions risks” for their participation in the Russian-European project to build a gas pipeline bypassing Ukraine.

In an interview with the German outlet Rheinische Post, US Ambassador to Germany Richard Grenell defended his threatening letters to the companies involved in the Russian-European venture Nord Stream 2, saying that their wording does not differ from what Washington publicly states. However, he refused to comment on any specific punitive measures that the US government might impose.

He pointed out that he sees protecting his fellow citizens and defending his homeland’s interests as a diplomat’s central responsibility, and as the US government and Congress have clear reservations about energy security and the geopolitical impact of Nord Stream 2, he will continue to push US policy.

READ MORE: Austria's OMV Slams US Ambassador's Letters About Nord Stream 2

He stated that the US would not take part in any conversations about the pipeline as a reliable, market-based energy supplier. As the diplomat claimed, the problem with Nord Stream 2 is that it is not an economic venture, but a project that was developed “for only one reason”: to create an alternative route for transporting Russian gas on its way to Europe that does not pass through Ukraine.

“So the question is whether European governments want to become more dependent on a country that uses chemical weapons to kill a political opponent in Europe. Will Europe become more dependent on a country that has invaded a sovereign state and illegally annexed a territory?” he insisted, as quoted by Rheinische Post, hinting at the allegations about poisoning Sergei Skripal in Britain, which Russia has strongly refuted, and the reunification with Crimea.

According to his claims, there is a danger that Russia might once again decide to use energy as a weapon against Europe or to show other “destructive behaviour”. It would unlikely target Germany, but would affect its eastern neighbors, he warned, saying that European unity is at stake because of the project.

He has claimed that Russian President Vladimir Putin wanted to end the transit of Russian gas through Ukraine, saying that Nord Stream 2 and Turk Stream 2 would enable him to do so.

He agreed that Europeans have to decide for themselves how and from where they import energy resources, but also claimed that many EU governments are against the project, pointing at the EU resolution condemning Nord Stream 2.

“Germany should take into account the concerns of the other EU member states and its neighbours, regarding the negative impact of the pipeline project on them”, he said, welcoming critical opinions of some politicians and business leaders, heard in Germany, according to him.

The German newspaper Bild on Sunday reported that Grenell had sent warning letters to German companies over their participation in the Russian-European project Nord Stream 2, which was likely coordinated with the US authorities. He requested that they consider the danger to European energy security, which is how the US views the project, and “the reputational costs and sanctions risk".

READ MORE: Russian and US Envoys Clash Over Nord Stream 2 in Dutch Media

Both conservative and left-wing German politicians have unanimously lambasted US Ambassador Richard Grenell and called on the country’s government to react. The Russian Foreign Ministry lashed out at him for trying to scare off German firms working on the Nord Stream 2 gas pipeline.

"It is part of a larger campaign… to contain Russia globally… Of course, it is unacceptable and it is not what an ambassador should be doing, it is, in fact, the opposite of that", Foreign Ministry spokeswoman Maria Zakharova said.

Nord Stream 2 is a joint venture of Russia’s Gazprom and five European companies: French Engie, Austrian OMV AG, UK-Dutch Royal Dutch Shell, German Uniper, and Wintershall.

The project is due to be wrapped up before the end of 2019 and envisages the construction of two gas pipelines that will run from Russia, through the Baltic Sea and to a hub in Germany, bypassing Ukraine entirely.

The United States has consistently spoken out against the project, claiming that it will increase Europe’s dependence on Russian gas. President Putin, in turn, said that his American counterpart Donald Trump was pursuing the interests of US companies to sell more expensive LNG to Europe.