MOSCOW, January 14. /TASS/. Russian Foreign Ministry's official spokeswoman Maria Zakharova described as unacceptable the actions of US Ambassador to Germany Richard Grenell who earlier sent letters to German companies warning them of possible US sanctions over their participation in the Nord Stream 2 gas pipeline project.

"Of course, this is unacceptable. This is not part of the ambassador's responsibilities, to say the least. In fact, it contradicts them," Zakharova told Rossiya-1 TV channel.

She also described Grenell's actions as part of a long-term program against Russia. "There is a big program on deterring our country, which has been historically implemented," she explained.