The North Korean authorities have announced they are ready to deal with US hostility "with nuclear weapons any time” and are working to improve the country’s nuclear weapons “in quality and quantity.”

"If the US and other hostile forces persistently pursue their reckless hostile policy towards the DPRK, we are fully prepared to respond with nuclear weapons at any time," said the director of the North's Atomic Energy Institute, as cited by the state KCNA news agency.

The statement was made by the director of the North's Atomic Energy Institute as reported by the state KCNA news agency. North Korea is working to improve its nuclear weapons "in quality and quantity," said the official.

Pyongyang has already started to operate a nuclear reactor at the Yongbyon Nuclear Scientific Research Center, North Korea’s major nuclear facility, about 90 kilometers from the capital Pyongyang.

READ MORE: N. Korean 'subs out for operations, artillery doubled,' talks with South resume



"All the nuclear facilities in Yongbyon [Nuclear Scientific Research Center], including the uranium enrichment plant and five megawatt reactor were rearranged, changed or readjusted and they started normal operation," the director of the Atomic Energy Institute told the North's Korean Central News Agency.

US & S. Korea consider ‘deploying American strategic assets’ amid border crisis http://t.co/F5VbmEHj8kpic.twitter.com/hFqWiERDx0 — RT (@RT_com) August 24, 2015

On Monday, North Korea's National Aerospace Development Administration said it had almost completed developing a new earth observation satellite.

"The world will clearly see a series of satellites of [North] Korea soaring into the sky at the times and locations determined by the Central Committee of the Workers' Party of Korea," according to a statement from the administration.

However, Seoul says these satellites may be long-range rockets, which could be a provocation and pose a threat to its neighbors.

"North Korea's ballistic missile launches are a grave provocative act and military threat as well as a clear violation of UN Security Council resolutions banning any activity using ballistic missile technology," Foreign Ministry spokesman Noh Kwang-il said.

Tensions have recently escalated on the Korean peninsula. In August, South and North exchanged fire over the South's propaganda loud speakers installed at the border. Pyongyang demanded they be removed. The trans-border shelling prompted evacuation of civilians from nearby villages and both countries' militaries were put on high alert and combat readiness.

Koreas ‘on brink of war’: Pyongyang marshals troops after exchange of fire http://t.co/IpyFRIDIbDpic.twitter.com/8E38hGB2pn — RT (@RT_com) August 21, 2015

Pyongyang also issued nuclear threats to Washington, saying it would respond accordingly if the America didn’t halt its military exercises with South Korea. The North added it was ready to use its latest weapons, which are “unknown to the world.”

However, the tensions didn’t result in war. At the end of August, both sides reached an agreement to end the military standoff.