In a speech on the third anniversary of his election, President Barack Obama said that he does not want to use the word “retarded” because it is “an insult to the millions of Americans with intellectual disabilities who are struggling to learn.”

He added: “I am also not in that habit of using the word ‘retard’ because it’s not a word that resonates with people.

The word ‘reparative therapy’ is a word we can all agree on, and it is a very useful word.”

The president’s comments came as the Republican Party’s campaign arm launched an attack on the Obama administration for what it described as its “shameful silence” on the issue of autism, which affects about 1% of the US population.

“The President’s silence has been deafening,” said the Republican National Committee in a statement.

“The President is not only silent on this issue but refuses to even acknowledge that there is such a thing as autism.

The President’s inability to acknowledge this has created a stigma and fear that is harming countless children and adults with autism.”

The Republican National Convention last month kicked off with a speech from the Republican vice-presidential nominee, Mike Pence, who highlighted the administration’s “shameless silence” and said it had “failed to act”.

Mr Obama, however, has not explicitly said the term “retard” should be used.

In his speech, Mr Obama said he does have a “strong” opinion on the matter, but added:”I do think there are many people who are just born with disabilities and I think that’s a real challenge.

I think it’s important that we be clear that there’s a distinction between being born with a disability and being diagnosed with a physical disability.”

He added: ‘If I’m going to use that word, I don’t want to be called ‘retards’ or anything like that.’

In his address, Mr Biden also defended the “strong stance” that the US takes in international disability rights.

“For me, it is deeply troubling that we see some countries that are not fully complying with international disability standards that the United States and other countries in the world are taking very seriously,” he said.

“And so I think there’s no reason for the United Sates to be less committed to our international obligations than we are.”

The US is one of only a handful of countries that do not have a disability rights treaty with other nations, but the treaty has yet to be signed.

The US has made no comment on the use of the term retard or any other disability in public.

The term is used by many people as a pejorative term for people with autism, a term that has been used by people with ADHD and other mental illnesses.

“There’s a great deal of anxiety around it and a lot of misconceptions around it,” said Lisa Cairns, a mental health advocate and professor of psychiatry at the University of Florida.

“It’s been around for decades, it’s very often used in the context of people who have autism and people with intellectual disability.”

“It was coined in the 1970s by a psychiatrist named David Blanchard who had a diagnosis of schizophrenia, and so the word was coined to describe people with schizophrenia who were not intellectually disabled.”

People with autism are often stereotyped and it’s used as a label to make people feel worse and less capable of empathy and compassion and understanding and empathy.

“But there are a lot more people than you might think who are not diagnosed with autism but do have a spectrum of intellectual disability and intellectual disability can be quite severe.”

Dr Cairn said there were some people who might find the term difficult to accept.

“A lot of people are very cautious about it because they are aware that if it’s being used, it could get stigmatised or they might think, ‘I’m not smart enough to be able to understand what you’re saying’,” she said.