Pyongyang, Sep 15 (IANS): North Korea said on Tuesday its atomic energy scientists are "steadily improving the levels of nuclear weapons with various missions in quality and quantity".

"If the US and other hostile forces persistently seek their reckless hostile policy towards North Korea and behave mischievously, North Korea is fully ready to cope with them with nuclear weapons any time," Xinhua news agency quoted the director of the Atomic Energy Institute as saying.

The director said all the nuclear facilities around Nyongbyon city, including the uranium enrichment plant and the graphite-moderated reactor were rearranged, changed or readjusted to start normal operation as announced by North Korea in April 2013.

"Pyongyang's access to the nuclear weapons is an outcome of the US hostile policy towards it," the director said, adding North's nuclear programme is of self-defence nature.

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.

It fuelled speculations that North Korea will soon launch a long-range rocket or a ballistic missile.