The former presidential candidate previously announced he won't vote Trump, the presumptive Republican presidential nominee, or likely Democratic nominee, Hillary Clinton, this November.
"What Trump did was so insensitive," Bush told NRC Handelsblad
ahead of a speech he's set to give at the Nexus Institute in Amsterdam later this week, according to an English translation.
"First, not all Hispanics are Mexican. Secondly, not all Hispanics eat tacos. Thirdly, showing your sensitivity by eating an American dish is the most insensitive thing you can do. Fourthly, to say this, next to all things he already said, is a further insult," he said. "It's like eating a watermelon and saying, 'I love African-Americans.'"
A spokeswoman for Bush, a former Florida governor, did not dispute the quote's translation, which was reported by the Huffington Post.
The Trump campaign did not immediately respond to a request for comment.
"This guy," Bush said. "If we lose in November, we Republicans have ourselves to blame."
Trump caused a stir when he tweeted on May 5 a photo of himself eating a taco bowl, adding that the best bowls "are made in Trump Tower Grill" and ending his tweet with "I love Hispanics!"
Later that day, Bush, who's fluent in Spanish, tweeted a year-old video of himself speaking in Spanish about the Mexican holiday.
During his White House bid, Bush repeatedly criticized Trump for comments he made about Hispanics and confronted him on stage during a debate after Trump retweeted a controversial comment about Bush's wife, who's from Mexico.
In the new interview, Bush also lamented the role of the media in "perpetuating" Trump's candidacy and chided the current political climate in the U.S.
"I only want(ed) to run a campaign with the integrity that I might be president. As a president, you can't allow empty chatter. That's one of the reasons people don't trust politicians," he said. "Politicians say things they will do, and don't do it. That's not how I wanted to run a campaign."