U.S. President Donald Trump again insulted a journalist on Friday, this time from NBC News, whom he called a "horrible little reporter" after repeatedly asking her to be quiet while she tried to formulate a question.

The episode took place during an appearance before the media at the White House, before departing for a campaign rally in Fort Myers, Florida, when the reporter tried to ask him about sexual abuse allegations against the mother of the Democratic candidate for governor of Ohio, Amy Acton.

Trump gestured for her to be quiet, raising his index finger, while the journalist insisted on asking about the matter.

The president asked her which outlet she worked for and, when she answered NBC News, he described the network as "one of the worst there is."

Last Wednesday a similar episode occurred, when the president called a CNN journalist "dumb" and an ABC News reporter "stupid" for asking him about the release of an American detained in Russia.

"You don't know what you're talking about. You have a low IQ, you're dumb and you work for CNN," he snapped at Kaitlan Collins, one of the network's best-known faces.

A day earlier, on Tuesday, Trump also told a reporter to shut up who was insistently questioning him during an event in the Oval Office: "Shut up! Shut up! What's wrong with you, are you sick?"

The increase in insults against reporters comes days before the November 3 midterm elections, in which polls point to a Democratic victory.

In addition, Trump has been trying since September to ban CNN, Ms Now, and Politico journalists from accessing the White House, dissatisfied with their coverage of his government, although a judge has temporarily halted the veto.