Button up, says Trump

US President Donald Trump has hit back at North Korean leader Kim Jong-un’s claim to have a “nuclear button” on his desk, saying he too has a nuclear button, but his is “much bigger” and “more powerful”.

“North Korean Leader Kim Jong Un just stated that the “Nuclear Button is on his desk at all times,” Mr Trump, pictured, wrote on Twitter late on Tuesday.

“Will someone from his depleted and food starved regime please inform him that I too have a Nuclear Button, but it is a much bigger & more powerful one than his, and my Button works!,” Mr Trump said.

Mr Kim used a New Year’s Day address on Monday to declare that his nuclear missile program had been successfully completed and that all of the US was within range of North Korea’s missiles.

But Mr Trump doesn’t actually have a physical nuclear button.

The process for launching a nuclear strike is secret and complex, and involves the use of a nuclear “football,” which is carried by a rotating group of military officers everywhere the president goes..

If the president were to order a strike, he would identify himself to military officials at the Pentagon with codes unique to him.