Reuters is reporting that foreign diplomats from several countries have expressed "alarm" about the rise of Donald Trump in the U.S. and apparently don't get his appeal.

Officials from Europe, the Middle East, Latin America and Asia have complained in recent private conversations, mostly about the xenophobic nature of Trump's statements, said three U.S. officials, who all declined to be identified.

"As the (Trump) rhetoric has continued, and in some cases amped up, so, too, have concerns by certain leaders around the world," said one of the officials.

The three officials declined to disclose a full list of countries whose diplomats have complained, but two said they included at least India, South Korea, Japan and Mexico.

U.S. officials said it was highly unusual for foreign diplomats to express concern, even privately, about candidates in the midst of a presidential campaign. U.S. allies in particular usually don't want to be seen as meddling in domestic politics, mindful that they will have to work with whoever wins.

Senior leaders in several countries -- including Britain, Mexico, France, and Canada -- have already made public comments criticizing Trump's positions. German Economy Minister Sigmar Gabriel branded him a threat to peace and prosperity in an interview published on Sunday.

Trump's campaign did not respond to requests for comment on the private diplomatic complaints.

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Japan's embassy declined to comment. The Indian and South Korean embassies did not respond to requests for comment.

A spokesperson for the Mexican government would not confirm any private complaints but noted that its top diplomat, Claudia Ruiz Massieu, said last week that Trump's policies and comments were "ignorant and racist" and that his plan to build a border wall to stop illegal immigration was "absurd."

The foreign officials have been particularly disturbed by the anti-immigrant and anti-Muslim themes that the billionaire real estate mogul has pushed, according to the U.S. officials.

European and Middle Eastern government representatives have expressed dismay to U.S. officials about anti-Muslim declarations by Trump that they say are being used in recruiting pitches by the Islamic State and other violent jihadist groups.

American voters should pay no attention to what foreigners think about our candidates or elections.  It's none of their business, and even confiding their fears to American diplomats off the record is out of bounds.  Imagine American diplomats weighing in on a national election anywhere else.  They would be heavily criticized – as these foreigners should be.

Besides, if you've been listening to the rhetoric coming out of Hungary and other countries in Eastern Europe, you know that Trump isn't saying anything that hasn't been said before about immigration and Muslims.  That it offends the sensibilities of the suicidal open-border advocates in Europe shouldn't matter.

Trump's bombastic rhetoric about tearing up treaties and murdering civilians is an embarrassment to the U.S., but somehow I think foreign diplomats will find a way to work with him if he's elected president.  That's what diplomacy is all about.