Washington (CNN) Donald Trump on Sunday had his harshest words yet for Jeb Bush , calling the former Florida governor "an embarrassment to himself and his family."

Trump's comments, in an interview on NBC's "Meet the Press," came the day after Bush declared at a campaign event: "Donald Trump is a jerk."

"He's an embarrassment to the Bush family, and in fact he doesn't even want to use the Bush name , which is interesting," Trump said.

"Jeb is an embarrassment to himself and his family, and the Republican Party has essentially -- they're not even listening to Jeb," he said.

The two sparred last week during CNN's Republican presidential debate, with Bush calling Trump a "chaos candidate" attempting to "insult your way to the White House" and Trump essentially pointing to the scoreboard, noting his massive lead in the GOP race.

On Sunday Trump predicted that Bush will soon exit the Republican presidential race, saying that "he's going to be off the stage soon."

Trump said Bush "is a weak and ineffective person. He's also a low-energy person , which I've said before. ... If he were president, it would just be more of the same. He's got money from all of the lobbyists and all of the special interests that run him like a puppet."

Bush had harsh words for Trump, too, in a Sunday interview on CBS' "Face the Nation."

JUST WATCHED Bush to Trump: You can't insult your way to presidency Replay More Videos ... MUST WATCH Bush to Trump: You can't insult your way to presidency 02:01

He pointed to Trump apparent ignorance in last week's GOP presidential debate about what the nuclear triad is.

"That's one of those questions that I think you have to answer in a thoughtful way if you're running for president of the United States," Bush said. "But it's not just that. I mean, he said that ISIS is not a threat. Two months ago he gets his news from the shows. I know that warms your heart that he wakes up in the morning and gets his foreign policy and military advice from people that go on your show.

"But that's not a serious man. Look, when he insults me personally. I don't take it personally. He shouldn't take it personally either but someone needs to call him out."