Experts have warned Congress that it is ignoring a newly-developed weapon from North Korea which could shut down the US power grid and kill the vast majority of Americans within a year.

Two members of the disbanded congressional Electromagnetic Pulse (EMP) commission said at a recent House Homeland Security subcommittee hearing that a nuclear EMP attack from Kim Jong Un was the “biggest threat” to the US yet it remains “unacknowledged” by the government.

More attention has been focused on the regime’s continued testing of intercontinental ballistic missiles this year, but the dictatorship also recently claimed to have tested a hydrogen bomb underground in September.

The regime said in a public statement that such a bomb could be detonated at high altitudes for “super-powerful EMP attack according to strategic goals”.

William Graham, chairman of the former EMP commission and its former chief of staff, Peter Vincent Pry, warned the hearing that such an attack could “shut down the US electric power grid for an indefinite period, leading to the death within a year of up to 90 per cent of all Americans.“

They urged the House to protect the grid, and warned that US ballistic missile defence systems are currently designed to intercept missiles from North Korea that approach the US over the North Polar region, but not over the South Polar region.

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Former Republican representative Curt Weldon, one of the founders of the former commission, wrote in The Hill last month: "A nuclear EMP attack would destroy electronics everywhere, cause planes to crash, stop cars and rail traffic, blackout electric grids and other critical infrastructures that make modern civilization, and life itself, possible. Eventually, millions would die from starvation, disease, and societal collapse."

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

The two former commission members added that North Korea is thought to have 60 nuclear weapons, and its intercontinental ballistic missiles could reach Denver and Chicago, and “perhaps the entire US”.

The regime is developing H-bombs which are “comparable to sophisticated US two-stage thermonuclear weapons”, they said.

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Experts such as former NASA rocket scientist James Oberg have previously warned that the regime could use a satellite to carry a small nuclear warhead and detonate it over the US.

Mr Graham and Mr Pry condemned the one-upmanship between Donald Trump and Kim Jong Un, who have called each other “rocket man” and “mentally deranged”, which has worsened tensions between the two countries.