The Korean Central News Agency, the official news service of North Korea, on Friday published a statement issued by the nation’s nuclear weapons institute. Following is the complete text of the statement, with key passages highlighted, accompanied by context and analysis by the correspondents of The New York Times:

Scientists and technicians of the D.P.R.K. carried out a nuclear explosion test for the judgment of the power of a nuclear warhead newly studied and manufactured by them at the northern nuclear test ground under the plan of the Workers’ Party of Korea (W.P.K.) for building strategic nuclear force.

The use of the phrase “nuclear warhead” rather than “nuclear device” is noteworthy, suggesting a specific, miniaturized design that can be mounted on a missile. D.P.R.K. refers to the Democratic People’s Republic of Korea, the North’s official name, and the Workers’ Party of Korea is the ruling party, led by Kim Jong-un.

The Central Committee of the W.P.K. sent warm congratulations to nuclear scientists and technicians of the northern nuclear test ground on the successful nuclear warhead explosion test. The nuclear test finally examined and confirmed the structure and specific features of movement of nuclear warhead that has been standardized to be able to be mounted on strategic ballistic rockets of the Hwasong artillery units of the Strategic Force of the Korean People’s Army as well as its performance and power.

The Hwasong artillery units are believed to be involved in the development of intercontinental missiles, but Hwasong also refers to a class of medium-range North Korean missiles, their version of a Scud missile. The Hwasong units have been conducting a series of missile tests in recent months, raising regional fears that the North can already mount a nuclear weapon on a missile capable of striking its neighbors, South Korea and Japan.

The North recently tested a missile that may be able to reach American bases in the Pacific and has been working on one that can reach the continental United States. But experts say it could take five years for the North to develop the technology needed, including a warhead capable of surviving the stress of re-entering the atmosphere.