North Korea has carried out a record-breaking blitz of weapons tests this year, including its newest intercontinental ballistic missile last month.

The new unit will provide "near-real-time detection and warning of ballistic missile launches", according to a statement from US Forces Korea (USFK).

"Just 48 miles (77 kilometres) north of us exists an existential threat; a threat that we must be prepared to deter, defend against, and -- if required -- defeat," said Lieutenant Colonel Joshua McCullion, who will lead the new space force unit.

The new unit enhances the "ironclad commitment to the US-Korean alliance," he said.

Around 28,500 US troops are stationed in the South to help protect it from the nuclear-armed North with which the South is technically still at war since the 1950-53 Korean War ended in an armistice, not a peace treaty.

Former president Donald Trump ordered the creation of Space Force in 2018, arguing the Pentagon needed it to tackle vulnerabilities in space and assert US dominance in orbit.

The new unit in South Korea is one of the few space force units to operate outside the US mainland.

Last month the US armed forces activated a space force component command at its Indo-Pacific Command in Hawaii.

South Korea's Air Force launched its own space squadron earlier this month as it seeks to bolster space command coordination with the US.

Pyongyang, which is banned from testing ballistic missiles by repeated UN Security Council resolutions, has claimed its weapons tests are a legitimate response to Washington's moves to boost the protection it offers to allies Seoul and Tokyo.