In a rare speech, Kim said that Trump's attacks have made him realised that he was right to develop nuclear weapons for his country.

He was quoted as saying by state-run KCNA, that the remarks "have convinced me, rather than frightening or stopping me, that the path I chose is correct and that it is the one I have to follow to the last."

He added that "now that Trump has denied the existence of and insulted me and my country in front of the eyes of the world and made the most ferocious declaration of a war in history", his country would consider the "highest level of hard-line countermeasure" to make the US President "pay dearly for his speech".

Earlier, during his speech, the US President had said that if the US is forced to defend itself, it would 'totally destroy' North Korea.

He also insulted Kim by calling him a 'rocket man' on a 'suicide mission'.

The comment has not been well received by Kim, who promised to 'surely and definitely tame the mentally deranged US dotard with fire".

Meanwhile, following Kim's comment, search for the term 'dotard' has witnessed a surge, Merriam-Webster tweeted.

According to the Oxford Dictionary, a dotard is 'an old person, especially one who has become weak or senile'.

The Merriam-Webster defines it as an 'imbecile'.