Former Mexican president Felipe Calderon has savaged Donald Trump, saying the Republican US presidential front-runner's campaign is racist and his comments on immigration are fuelling anti-American sentiment around the world.
Mr Calderon, a conservative who was president of Mexico from 2006 to 2012, even said he thought Mr Trump was trying to exploit the same social feelings and resentments as Adolf Hitler.
"I think his logic of exalting white supremacy isn't even acting against immigration - Donald Trump is the descendant of migrants - it is acting and speaking against immigrants who have a different skin colour than him, which is frankly racist and is a bit like the exploitation of raw nerves that Hitler did in his day," Mr Calderon said after a meeting of the National Action Party (PAN), in Mexico City.
Mr Calderon's comments parallel those made earlier by former president Vicente Fox, who preceded him in office and also belonged to the PAN party.
In interviews with Univision and Mexican media, Mr Fox called billionaire businessman Mr Trump "crazy", a "false prophet" and an embarrassment to his party.
When asked about Mr Trump's assertion that he was going to get Mexico to pay for his proposed border wall, Mr Fox used an expletive to make his point that the country would never do so.
Mr Trump said Fox ought to be "ashamed of himself" for his vulgarity and demanded an apology.
Mr Trump has angered many Mexicans for his campaign rhetoric denigrating some immigrants as "rapists" who bring crime and drugs to the United States. Threats of mass deportations of Mexicans and other migrants illegally in the country, along with his promise to build a wall separating the nations, have added to the bad feelings.
Mr Calderon said Mr Trump's discourse was "sowing hate" against the United States around the world which was not in Washington's interest.
During a visit to Mexico's capital, US vice president Joe Biden apologised for the inflammatory rhetoric about Mexico in the presidential campaign.
"Some of the rhetoric coming from some of the presidential candidates on the other team are I think dangerous, damaging and incredibly ill-advised," he said on Thursday.
"But here's what I'm here to tell you: they do not, they do not, they do not represent the view of the vast majority of the American people."