Donald Trump has demanded an investigation into what he called a "triple sabotage" during his visit to the United Nations General Assembly on Wednesday.

In a post on social media, the US president referred to an escalator abruptly stopping as he and First Lady Melania Trump stepped on, a teleprompter malfunctioning during his speech, and an audio issue in the auditorium.

A UN official said the sound system was designed to allow people to hear translated speeches through earpieces.

The UN previously said a safety mechanism might have been triggered by Trump's videographer who had been travelling backwards up the escalator while the teleprompter belonged to the US delegation.

Trump criticised the incidents on Truth Social and said he was sending a letter to the UN Secretary General Antonio Guterres demanding an immediate probe.

"A REAL DISGRACE took place at the United Nations yesterday - Not one, not two, but three very sinister events!" he wrote.

"This wasn't a coincidence, this was triple sabotage at the UN. They ought to be ashamed of themselves."

He also called for the arrest of the people responsible for the escalator incident, referencing an article in the Times that said UN workers joked about turning off the escalators.

"This was absolutely sabotage... All security tapes at the escalator should be saved, especially the emergency stop button. The Secret Service is involved," Trump added.

Mike Waltz, US ambassador to the UN, echoed the president's call for an official probe, saying the incidents were "unacceptable".

"The United States will not tolerate threats to our security or dignity at international forums. We expect swift cooperation and decisive action," he wrote on X.

On Wednesday, White House press secretary Karoline Leavitt raised concerns that someone deliberately stopped the escalator.

"If someone at the UN intentionally stopped the escalator as the President and First Lady were stepping on, they need to be fired and investigated immediately," she wrote on X after the incident.

Stephane Dujarric, spokesperson for Guterres, said Trump's videographer "may have inadvertently triggered the safety function" while filming the couple.

After the escalator mishap, Trump ran into more technical difficulties when he said the teleprompter was not working - although it was restored towards the end of his address.

"I can only say that whoever's operating this teleprompter is in big trouble," he said.

A UN official later told the BBC the White House was operating the teleprompter at the time, bringing their own laptops and plugging them into the UN's system.

Trump also referred to audio issues in his lengthy post, saying "the sound was completely off in the Auditorium".

"World Leaders, unless they used the interpreters' earpieces, couldn't hear a thing," he added.

In response to Trump's comments, a UN official said: ''The sound system was designed to allow people at their seats to hear speeches being translated into six different languages through earpieces." (BBC)