"We paid attention to the statements by high-ranking administration officials about the alleged illegitimacy of elections in the new regions of Russia. We are facing threats with another wave of sanctions, including against international observers, who are expected to give impartial conclusions about the character of the electoral process," the embassy said.
"US authorities do not part with a long-standing habit of meddling into internal affairs of other countries. They consider themselves entitled to making recommendations and warnings regarding the conduct of electoral campaigns abroad," the mission added.
The embassy noted that "the United States is gravely mistaken in thinking that they can intimidate us and all those who understand the true nature of the conflict in Ukraine with the prospect of imposing restrictions."
Officials underscored that residents of the Donetsk and Lugansk People's Republics, as well as the Kherson and Zaporozhye regions, "made their lawful choice at the referendums." The embassy also recalled that "the same was done by inhabitants of the Crimea and Sevastopol."
Earlier Friday, US Secretary of State claimed elections being held in former Ukrainian regions from Friday to Sunday were "sham" referendums, noting the US were "never" acknowledge the legitimate outcome in which all four regions voted in favor of joining Russia.
Official election results in the Kherson and Zaporozhye regions and the Donetsk and Lugansk People's Republics showed exceedingly high approval ratings.