Former New York Gov. George Pataki launched an attack against Donald Trump on Wednesday concerning the real estate mogul's controversial remarks about Mexican immigrants.

Pataki sent an open letter about Trump to the other Republican presidential candidates encouraging them to "denounce his comments today." He also tweeted a link to the letter, which Trump saw, sparking a heated Twitter feud between the two 2016 candidates.

Trump fired back with these Twitter posts:

In the open letter, and during recent press interviews, Pataki called Trump's comments "completely unacceptable."

Pataki also accused the 14 other GOP candidates of being "silent when it comes to denouncing these sad and divisive remarks" in the letter.

In a recent Fox News interview, Pataki said that Trump's comments stem from "100-year-old rhetoric that is just completely wrong."

The New York native touched on his own family's migration to the U.S. "My grandmother came from Ireland -- 100 years ago, they were saying the Irish were drunks. My grandfather came from Italy -- 100 years ago, they were saying they were all in the Mafia. This is the type of divisive rhetoric that I think is wrong," Pataki said on Wednesday.

The uproar started when Trump said that Mexican illegal immigrants are "bringing drugs, they're bringing crime, they're rapists, and some, I assume, are good people." The comments were made during his presidential campaign announcement last month.

The businessman's comments resulted in a severe backlash that cost him business contracts with Univision, NBC and Macy's. Nonetheless, Trump remains firm about his position regarding Mexico and immigration.

"The border is a disaster," Trump told Fox News earlier this week. "People are pouring in, and I mean illegal people, illegal immigrants."

Trump has said that he loves Mexican people and respects Mexico, but "Mexico is doing a tremendous number against the United States," he said, adding, "they're taking our manufacturing, and they're taking our money."

Trump is enjoying a surge in the presidential primary polls in key states, and nationally, according to Fox News. Meanwhile, Pataki is trailing behind.