PYONGYANG, Sept. 15 (Xinhua) -- The Democratic People's Republic of Korea (DPRK) said Tuesday that country's scientists in atomic energy are "steadily improving the levels of nuclear weapons with various missions in quality and quantity" and they have made innovations day by day in their research and production.

"If the U.S. and other hostile forces persistently seek their reckless hostile policy towards the DPRK and behave mischievously, the DPRK is fully ready to cope with them with nuclear weapons any time," the state-run news agency KCNA quoted the unnamed director of the Atomic Energy Institute as saying.

The director said all the nuclear facilities around the city of Nyongbyon, a city about 100 km northeast of the capital Pyongyang, including the uranium enrichment plant and the graphite-moderated reactor were rearranged, changed or readjusted to start normal operation as announced by the DPRK in April 2013.

"The DPRK's access to the nuclear weapons is an outcome of the U.S. hostile policy towards it," the state media said, stressing that the DPRK's nuclear program is of self-defense nature.

It blasted the United States for retaining an "anachronistic hostile policy toward the DPRK" and "openly seeking the downfall of its social system."

On Monday, Pyongyang said it is accelerating efforts at the final stage of development for new satellites for earth observations on the occasion of the 70th founding anniversary of the ruling Workers' Party of Korea, fueling speculations that the DPRK will soon launch a long-range rocket or a ballistic missile.