Harry Potter author J.K. Rowling could not contain her laughter after US President Donald Trump defended his spelling skills on Twitter.

On Tuesday (July 3), Mr Trump criticised the media, which he said "constantly likes to pour over my tweets looking for a mistake".

He also added that he has written "many best selling books" and prides himself on his ability to write.

"I capitalise certain words only for emphasis, not b/c they should be capitalised!" Mr Trump added.

Little did he know, the tweet contained a spelling mistake, when he used "pour" instead of "pore".

The British writer of the popular Harry Potter children's books then shared his tweet, laughing at the glaring typo made by the US President.

Mr Trump has since deleted the tweet with the error, and replaced it with a new one using the correct word.

However, it was too late as the mistake had already been picked up by Twitter users, including Merriam-Webster Dictionary, which seemed to allude to the mistake in a separate tweet explaining the difference between "pour" and "pore".

Despite the correction, many Twitter users continued to mock Mr Trump for the typo, with one saying: "Hey, @realDonaldTrump. Would you mind PORING me a drink?"

Another one added: "Oh leave the pore man alone!"