According to the report, the tests were conducted to ensure the survivability of anthrax, a potentially lethal biological pathogen, in high-temperature environments such as those generated when missiles re-enter earth's atmosphere.
"To send North Korea a unified message from the global community, that we will not accept you as a nuclear nation", US Secretary of State Rex Tillerson said. However, North Korea has set to flawless its re-entry technology.
North Korea on Wednesday refuted the reports by some USA media that Pyongyang is pushing forward her "biological weapons development programme" amid its development of weapons of mass destruction (WMD) capacities.
In response, North Korea said it would "take revenge" on the USA for saying it is developing biological weapons.
Not just nukes: North Korea reportedly trying to mount Anthrax on ICBMs
A Japanese newspaper reports that North Korea is testing the deadly anthrax virus and other biological elements for use in delivery via long-range missile warheads.
Rebecca Hersman, a former Defense Department deputy assistant secretary for countering weapons of mass destruction, was quoted in a Washington Post article speaking about the country's bio-weapon program: "North Korea is bad enough when you're talking about their nuclear and missiles program".
The White House said in its new National Security Strategy, issued on Monday, that North Korea is pursuing "nuclear, chemical and biological weapons".
This picture from North Korea's official Korean Central News Agency (KCNA) taken on August 29, 2017 and released on August 30, 2017 shows North Korea's intermediate-range strategic ballistic rocket Hwasong-12 lifting off from the launching pad at an undisclosed location near Pyongyang.More news: Alexis Sanchez set for lucrative free transfer to Manchester City