Seoul, South Korea :

North Korea is ready to test-fire an intercontinental ballistic missile (ICBM) at a normal trajectory, leader Kim Jong Un’s sister said Tuesday in state media, a flight pattern that could prove the weapons can threaten the continental United States.

In a statement carried by the Korean Central News Agency (KCNA), Kim Yo Jong – the top official in her brother’s regime – also dismissed experts’ skepticism surrounding North Korea’s ICBM technology progress, specifically about the reentry capability of its weapons.

ICBMs are fired into space, where they speed along outside the atmosphere before their payloads – nuclear warheads – undergo a fiery reentry process, much like a space shuttle or space capsule, before plunging down on their targets.

If the process isn’t executed with pinpoint accuracy and with materials that can withstand the immense heat generated, the warhead would burn up before reaching its target. The angle at which the warhead reenters the atmosphere can make the process more difficult.

To date, North Korea has fired ballistic missiles that go hundreds of miles into space then renter the atmosphere at steep angles, with most falling into waters between North Korea and Japan.

To successfully target the mainland US, a North Korean missile would have to take a much shallower flight path and a shallower reentry angle.