Donald Trump, who now trails Dr. Ben Carson in some polls, said this morning on "Fox and Friends" that the retired neurosurgeon is a "nice guy, but can't do the job" that the President of the United States must do.

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Trump argued that Carson just does not have the experience necessary to be president at this time.

"I like Ben, but Ben can't do the job. There's no question about it. He can't negotiate with China. That's not his thing," he said. 

Asked why he believes this, Trump responded that "fierce" negotiations with countries like China and Japan "are not in Carson's wheelhouse."

"I think he cannot make deals with China or 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," said Trump, adding that he has a history of "beating China" at the negotiating table.

Trump downplayed Carson's rise in the polls, pointing out other polls in which he's still in the lead in Iowa, Florida, South Carolina and New Hampshire. 

He said Carson is "very weak on immigration," while Sen. Marco Rubio is "horrible" on that issue. 

Watch Trump sound off on a range of other topics in the video above, including the new debate proposals by the GOP.

Don't miss the next Republican presidential debate on Fox Business Network, Tuesday November 10th at 9p ET.

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