The son of Dr Martin Luther King has accused the White House of failing to respond to a “lynching or a murder” witnessed by the whole world.

Protests over the killing of George Floyd in police custody continued across the US last night, despite curfew imposed in around 40 cities.

On Newstalk Breakfast this morning, Martin Luther King III said we all witnessed the breath being “sucked out of this man because a police officer refused to remove his knee” from the back of his neck.

“What we saw was a lynching or a murder,” he said. “A police man who was supposed to protect and serve killing an African American man.”

“So, out of legitimate anger, legitimate rage, people began to protest. Some of the protesting has been non-violent but a lot of it has also been violent and unfortunately, as my father said, violence is the language of the unheard.

“When people feel they are not respected with dignity, they are not heard, they are not seen, sometimes they resort to extreme measures.”

"Black Lives Matter" protesters outside Los Angeles Mayor Garcetti's house, 02-06-2020. Image: Richard Vogel/AP/Press Association Images

He noted that the signs held up at protests around the world in the past few days are the same as those held up by people who marched with is father over 50 years ago.

“Fifty-plus years ago my father was marching in Memphis Tennessee, before he was killed, with sanitation workers and they had a sign that said, ‘I am man,’” he said.

“That was saying, ‘I am a sanitation worker but treat me with respect, treat me with dignity, treat me as a human being.’

“Now, fifty-plus years later, African Americans, whites and others are holding up signs saying, ‘treat me with dignity, treat me with respect. I am human being; I am not being treated that way. I am treated as less than human.’”

The US President Donald Trump passes graffiti as he walks from the White House to pose with a bible outside St. John's Episcopal Church, 01-07-2020. Image: Shawn Thew / Pool via CNP

He said the response from President Donald Trump has been “more disappointing that anything else.”

“We have not seen an appropriate response from the White House in my view,” he said.

“A response that talks about how we quell, how we reduce, how we de-escalate, how we bring communities together. How we address this issue.

“That message has not come out from the White House yet and maybe it will not come. We hope it will and I can only hope and pray that someone will advise the president to take a different posture.”

A drawing of George Floyd plastered to a light pole during a demonstration in Minneapolis, 02-06-2020. Image: Toby Scott / SOPA Images/Sipa USA

Mr Floyd died after police officer Derek Chauvin knelt on the back of his neck for nearly nine minutes in the city of Minneapolis.

Video of the incident shows the unarmed Mr Floyd repeatedly telling the policeman “I can’t breathe” before losing consciousness.

Mr Chauvin has been charged with third-degree murder and manslaughter; however, Mr Floyds family are calling for all four police officers involved in the arrest to face justice.

Demonstrators put their hands behind their heads before being taken into custody in Minneapolis, 03-06-2020. Image: AP Photo/Mark J. Terrill

Mr King said his father would be “greatly frustrated with the situation and with the reaction of some people” if he was alive today.

“I think my dad would always find a way out of no way,” he said. “He and his team would find a way for us to constructively address these issues.”

“The operative word here is constructively. Not in a destructive manner.

“Dad used to say violence is the language of the unheard. When you allow people to be heard and treated with dignity and respect and to be treated as human beings, that is what people ultimately want.

“So, I think my day would have found a way to create that climate. He always was pushing us to a higher level. To higher plane and to a more noble and just humanity – and that is what is needed at this time.”

You can listen back to the full interview here:

Main image shows Martin Luther King III speaking during the NAACP national convention in Orlando Florida, 17-07-2013. Image: George Skene/Orlando Sentinel/MCT/Sipa USA