Donald Trump responded with shocking comments over the weekend to Khizr Khan's Democratic National Convention speech, and Meghan McCain has joined the chorus of Republicans slamming the GOP presidential candidate.

McCain — a fellow Republican and daughter of former presidential candidate Sen. John McCain (R-Arizona) — took to Twitter to call Trump a "barbarian" for his response to the Khan family. She also reminded us that Trump once questioned her father's military record.

John McCain — a decorated former U.S. Navy aviator during the Vietnam War — was attacked by Trump for being captured and held for five and a half years in a North Vietnamese prison camp, where he was repeatedly tortured.

"He's not a war hero," Trump said at the Family Leadership Summit in Ames, Iowa, in 2015, adding: "I like people who weren't captured."

Meghan McCain is not the only Republican to repudiate Trump's words.

Ohio governor and former Republican presidential candidate John Kasich also responded to Trump's words on Sunday, tweeting that the only way to talk about parents who have lost a child who served in the armed forces is "with honor and respect." He also called the Khan family's son a "hero."

The criticism of the Republican party's presidential nominee comes after Trump responded to an emotional appeal by the parents of the slain Muslim-American U.S. Army captain at the Democratic National Convention by mocking the fallen soldier's mother, Ghazala Khan.

"If you look at his wife, she was standing there," Trump said in an interview with ABC's This Week. "She had nothing to say. ... Maybe she wasn't allowed to have anything to say. You tell me."

Ghazala Khan responded to Trump's comments in an op-ed in The Washington Post on Sunday:

"Here is my answer to Donald Trump: Because without saying a thing, all the world, all America, felt my pain. I am a Gold Star mother. Whoever saw me felt me in their heart. ... Walking onto the convention stage, with a huge picture of my son behind me, I could hardly control myself. What mother could? Donald Trump has children whom he loves. Does he really need to wonder why I did not speak?"