Republican presidential candidate Donald Trump blasted his fellow GOP rivals Tuesday, saying retired neurosurgeon Ben Carson "can't to the job" of president, Florida Sen. Marco Rubio is "overrated" and former Florida Gov. Jeb Bush should just drop out of the race.

Sitting on Fox News' "Fox & Friends" couch on Tuesday morning, Trump said he likes Carson, but that "Ben can't do the job."

"I mean there is no question about it. He can't do the job. He's not going to be able to negotiate with China. It's not his thing. He doesn't do that," he said, reported The Daily Caller.

When pressed further about Carson, Trump added: "It's not his thing. It's not in his wheel house. He's never done it before. And I don't think it's meant for him. These are people that come at you - they're fierce. You know some of the deals I've made with China. I've made great deals with China. I beat China all the time. I love doing it, but that's what I do. Our trade deals are a horror, our military is a mess."

Trump also dismissed the idea that Carson may be able to "rise to the occasion."

"No, I don't think he could do that. I think he cannot make deals with China. I think he cannot make deals with Japan. If we don't start taking back our jobs, if we don't start taking back our money, our finances, our base from China, we are in a situation which I don't think is recoverable."

The interview came a day after a new NBC/Wall Street Journal poll showed Carson stealing the lead from Trump yet again, garnering 29 percent support from Republican voters compared to Trump's 23 percent.

In a separate appearance on ABC News' "Good Morning America," Trump ripped Rubio, saying, "I'm not a fan. I think he's overrated."

Russian President Vladimir Putin "would eat him alive," Trump added, reported ABC NewsAs for Bush, Trump said he should "absolutely" drop out of the presidential race, saying that "he doesn't have a chance."