North Korea’s nuclear missile will be ready to strike the United States in the next two months, author Gordon Chang has warned. 

Speaking to Fox News, he said: “They wouldn’t put Anthrax in an ICMB because the method of delivery wouldn’t be that effective but nuclear weapons they’re within maybe 2 months.

“Now it’s been disclosed that the CIA gave President Trump an assessment that you know within that time frame they’ll be able to hit the US with a nuke.”

Chang said the only thing holding Kim Jong-un’s regime back is heat shielding, which protects the missile on the way down. 

He said: “That means that they’ve got good guidance, that they’ve certainly got the range we know that from their last November 29th test, and the question is heat shielding which is the big issue.

“About whether they are able to protect the warhead on the way down, a lot of disagreement about it .”

“But if they can’t do it within two months, they’ll be able to do it within six, nine months, certainly sometime within 2018.”

The author also talked about North Korea’s other warfare programs including biological weapons like Anthrax, which has been found in the blood of North Korean defectors. 

Anthrax has been used a biological weapon throughout the 20th Century as it is spread easily by breathing in spores in the air. 

He said: “The North Koreans have killed others outside of North Korea with chemicals; this is an indication that the regime will do anything with the weapons it has."

There has been renewed attention on North Korea’s biological and chemical weapons this year after Kim Jong-un’s half-brother was assassinated in Kuala Lumpur airport with nerve agent VX earlier this year. 

A report by researchers at Harvard University, published in October, said "accurately assessing the threat from North Korea's biological weapons programme is challenging," as unlike its nuclear and missile tests it can be carried out in secret behind-closed-doors.