North Korea said it will “take revenge” on the US for saying Pyongyang is developing biological weapons.

North Korea said via its state media Korean Central News Agency that: “as a state party to the Biological Weapons Convention (BWC), [it] maintains its consistent stand to oppose development, manufacture, stockpiling and possession of biological weapons."

"The more the US clings to the anti-[North Korea] stifling move...the more hardened the determination of our entire military personnel and people to take revenge will be,” said the KCNA.

​KCNA called the US claims "groundless" and said it was just an excuse for harsher sanctions after President Donald Trump labelled North Korea as a state sponsor of terrorism.

The Trump administration made the assertion that the isolated Asian country was developing a missile capable of carrying the biological weapons as well in its National Security Strategy document.

The 55-page document focused on Mr Trump's "America First" approach to security and stated: "North Korea—a country that starves its own people—has spent hundreds of millions of dollars on nuclear, chemical, and biological weapons that could threaten our homeland."

The administration also wrote that: "North Korea is also pursuing chemical and biological weapons which could also be delivered by missile."

North Korea TV shows video of ballistic missile launch

According to a 2016 report by the Korea Institute for Defence Analyses, North Korea has 13 types of pathogens that can be weaponised such as anthrax and clostridium botulinum.

The US claims and subsequent North Korean denial come at a time when South Korean officials proposed a delay in military drills with the US in order to ensure a peaceful 2018 Winter Olympics, not ease tensions with North Korea and China.

South Korean President Moon Jae-in is seeking to soothe relations with Pyongyang and with China, the North's lone major ally, before the Olympics begin in South Korea in February.

China, which hosted years of on-again-off-again talks to try to end the North Korea standoff, resumed some blocks on group tours to South Korea and rebuked Seoul for firing warning shots at Chinese fishing boats.

Kim Jong-un inspects weapon North Korea says is powerful hydrogen bomb Show all 6 1 /6 Kim Jong-un inspects weapon North Korea says is powerful hydrogen bomb Kim Jong-un inspects weapon North Korea says is powerful hydrogen bomb Photos released by North Korea show Kim Jong-un talking to subordinates next to a device thought to be the new thermonuclear weapon. There is no way of independently verifying the pictures STR/AFP/Getty Images Kim Jong-un inspects weapon North Korea says is powerful hydrogen bomb North Korea claims it has successfully tested an advanced hydrogen bomb which could be loaded onto an intercontinental ballistic missile AFP/Getty Kim Jong-un inspects weapon North Korea says is powerful hydrogen bomb A diagram on the wall behind Mr Kim shows a bomb mounted inside a cone STR/AFP/Getty Images Kim Jong-un inspects weapon North Korea says is powerful hydrogen bomb North Korean leader Kim Jong-Un (C) attending a photo session with participants of the fourth conference of active secretaries of primary organisations of the youth league of the Korean People's Army (KPA) in Pyongyang STR/AFP/Getty Images Kim Jong-un inspects weapon North Korea says is powerful hydrogen bomb A new stamp issued in commemoration of the successful second test launch of the "Hwasong-14" intercontinental ballistic missile KCNA via Reuters Kim Jong-un inspects weapon North Korea says is powerful hydrogen bomb A new stamp issued in commemoration of the successful second test launch of the "Hwasong-14" intercontinental ballistic missile KCNA via Reuters

A spokesperson for South Korean President Moon Jae-in said the proposed delay was "confined to our efforts to host a peaceful Olympics. We are only talking about the exercises which are supposed to take place during the Olympics and Paralympics."

Mr Moon had travelled to China to discuss the proposal last week, after it had been presented to the US.

North Korea sees the regular joint exercises as preparation for war.

China has maintained that the deployment of a US anti-missile system known as the Terminal High Altitude Area Defence (Thaad) near Seoul is a threat to it because South Korea could use the powerful radar to see deep inside China's territory.

The South argues it needs Thaad to guard against the threat posed by North Korea.

China and Russia have proposed a "freeze for freeze" arrangement under which North Korea would stop its nuclear and missile tests in exchange for a halt to the exercises.