The U.S. Air Force is preparing to put nuclear-capable B-52 bombers on 24-hour alert for the first time since the Cold War in response to North Korea's "rapidly advancing nuclear arsenal", U.S. news site Defense One reported Sunday.

The concrete pads at the runway of Barksdale Air Force Base in Louisiana "could once again find several B-52s parked on them, laden with nuclear weapons and set to take off at a moment's notice," it said.

"This is yet one more step in ensuring that we're prepared," Air Force chief of staff Gen. David Goldfein told Defense 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."

"Goldfein and other senior defense officials stressed that the alert order had not been given, but that preparations were under way in anticipation that it might come," the website added.

