U.S. ambassador to Iceland Jeffrey Ross Gunter has provoked anger and criticism in Iceland after he retweeted a post from U.S. President Donald Trump calling COVID-19 "the Invisible China Virus."

"We are United to defeat the Invisible China Virus," wrote Gunter last week on his official ambassadorial Twitter account, followed by the flag emojis of the United States and Iceland displayed side by side.

Gunter's retweet came after Trump tweeted on July 20, using "the Invisible China Virus" to refer to COVID-19.

The Icelandic National Broadcasting Service (RUV) said the ambassador's tweet has stirred up "a backlash from some Icelanders."

"Many in Iceland believe it was undiplomatic for the ambassador to also use the term 'China virus' in his re-tweet, thereby prompting some to call on him to remove the Icelandic flag," the RUV has said.

Iceland Review, the longest-running magazine in Iceland, said in an article on Friday that the tweet "drew the ire of American nationals and Icelanders."

The magazine reported that Elizabeth Lay, an American living in Iceland, has started a petition denouncing the phrase of "the Invisible China Virus," as it is "deeply offensive and hurtful." Up to now, the petition has drawn more than 370 signatures.

Jessica Bowe, a dual citizen of the United States and Iceland who has signed the petition, called the ambassador an embarrassment in her tweet, saying she is against the "racist and anti-scientist sentiments as an American."

Meanwhile, an article in Reykjavik Grapevine, an English magazine in Iceland, aired the strong opposition of Smari McCarthy, member of parliament from the Pirate Party, to the tweet, who described Gunter's rhetoric as "nonsense" and "spreading nationalistic rhetoric doesn't help anybody."

"Viruses do not have nationalities. Nor are they invisible, merely microscopic. We're all in this pandemic together," McCarthy was quoted by Reykjavik Grapevine as saying.

Petur Maack, head of psychosocial services at the Health Care Institute of North Iceland, said that Iceland and the United States are "not united at all" in the attitudes toward the virus, and that the U.S. government "has managed to get it wrong every step of the way" in containing the COVID-19 outbreak.

The United States is the country hardest hit by COVID-19 in the world, reporting more than 4.2 million cases with over 146,000 deaths as of Sunday, according to a tally by Johns Hopkins University.