America’s Air Force is preparing to put nuclear-armed bombers on 24-hour standby for the first time in a quarter of a century amid escalating tensions with North Korea.

The move would see B-52 planes carrying nuclear weapons sitting on the runway at Barksdale Air Force Base in Louisiana and ready to fly when given the order.

It would be the first time the status was put in place since 1991, when the Cold War was nearing an end.

Gen. David Goldfein, the US Air Force chief of staff, said that while the command had not yet been given the military was preparing itself for the change.

“This is yet one more step in ensuring that we’re prepared,” he told the online publication Defence One.

“I look at it more as not planning for any specific event, but more for the reality of the global situation we find ourselves in and how we ensure we’re prepared going forward.”