Real estate mogul Donald Trump said during his presidential announcement that Mexican migrants to the U.S. are drug traffickers and rapists, as well as "some ... good people." (AP)

Donald Trump's entrance into the 2016 U.S. presidential campaign on Tuesday led to a slew of bemused and amused reactions in the American media, but perhaps the most important response came south of the border.

Trump, after all, had devoted considerable time during his rambling announcement to casting aspersions on Mexican migrants to the United States, suggesting that they were rapists, narco-criminals and general malefactors. He also trumpeted a plan to build a "great, great wall" on the border — with Mexican money.

The ludicrousness of this prompted official comment in Mexico City.

"The remarks by Donald Trump seem prejudicial and absurd," Miguel Ángel Osorio Chong, Mexico's interior minister, told reporters on the sidelines of an anti-discrimination event on Tuesday.

"He surely doesn't know the contributions made by migrants from practically every nation in the world, who have supported the development of the United States," Chong said.

On Planet Trump, of course, such a reasonable contention has little impact. In a follow-up interview with Bill O'Reilly of Fox News, Trump doubled down on his fear-mongering and borderline racist demonization of Mexico.

"The Mexicans are the new China.... They are ripping us so badly," Trump said. He added that Mexico, a country of more than 120 million people and the world's 15th-largest economy, "is living off the United States" and is "not our friend."

Trump has a record of xenophobia, including considerable grousing earlier this year when Mexican director Alejandro Iñárritu won numerous Oscars for his film "Birdman."

"This is a man who has a pathological need for attention," Lisa Navarrete, a spokeswoman for the National Council of La Raza, a Hispanic American civil rights organization, told the Guardian. "I look at him as a two-year-old who will say a naughty word to get their parents’ attention."

Reaction on Mexican social media was equally dismissive.

"This is an exceedingly silly man, who has no idea what he’s talking about," said Navarrete.

Real estate mogul and reality television star Donald Trump spoke about his personal wealth, China, Secretary of State John Kerry's bike accident and more in the top moments from his presidential announcement. (Sarah Parnass/The Washington Post)