Washington DC - President Donald Trump signed an executive order deeming the dangerous illicit drug fentanyl as a "Weapon of Mass Destruction."

The order, which was released by the White House on Monday, describes the drug as "closer to a chemical weapon than a narcotic."

It adds that "an almost undetectable trace... constitutes a lethal dose," causing countless overdoses in the US.

The order further argues that taking steps to "eliminate the threat" is in the interest of the US' national security.

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"The production and sale of fentanyl by Foreign Terrorist Organizations and cartels fund these entities' operations – which include assassinations, terrorist acts, and insurgencies around the world – and allow these entities to erode our domestic security and the well-being of our Nation," the order states.

It goes on to instruct executive departments and federal agencies to take specific actions, such as having Attorney General Pam Bondi "immediately pursue investigations and prosecutions into fentanyl trafficking."

The move comes as President Trump has ramped up efforts to stop the flow of drugs through the Southern border in his second term.

His administration has been under fire for bombing numerous boats in the Caribbean Sea and eastern Pacific Ocean that they claim – without providing evidence – are trafficking drugs. More than 90 people have been killed in the strikes.

US law already defines WMDs as "any weapon involving a biological agent, toxin, or vector," and the use or production of them can carry a possible death sentence.