North Korea’s state media said earlier in the day that the late Friday test was crucial for bolstering the country’s strategic nuclear deterrent.

"We have seen the reports of a test, and are coordinating closely with our Korean and Japanese allies," the spokesperson said in a statement.

The North Korean state news agency KCNA said that data collected during this and other recent experiments would be used for the development of a strategic weapon which would help overpower the US in case of an acute confrontation.