SEOUL -- The Republic of Korea (ROK) said Tuesday that it will make rapid and effective responses to possible launch of a long-range rocket by the Democratic People's Republic of Korea (DPRK) via the UN Security Council.

Foreign Ministry spokesman Noh Kwang-il told a press briefing that the DPRK's launch of any ballistic missile will be a grave act of provocation and military threat in violation of the UN Security Council's resolutions that ban the DPRK's all acts using any ballistic missile technology.

To take rapid and effective measures via the UN Security Council in response to any DPRK launch of a long-range ballistic missile, the ROK will closely cooperate with related countries, including members of the UN Security Council, the spokesman said.

His comments came a day after the DPRK's National Aerospace Development Administration (NADA) said that it was accelerating efforts at the final stage of developing satellites for earth observations, indicating the long-range rocket launch around the 70th anniversary of the founding of the ruling Workers' Party of Korea on Oct 10.

Until now, no specific movements have been detected for the DPRK's long-range rocket launch, Defense Ministry spokesman Kim Min-seok told a press briefing, saying that the country was closely monitoring all situations about the DPRK's long-range missile firing along with the United States.

The anonymous NADA director told the official KCNA news agency that successful progress has been made in its expansion of launching grounds for higher-level satellite lift-off, noting that the world will witness more satellites of Songun (military-first policy of the DPRK) Korea fired into the sky at the times and locations determined by its ruling party's central committee.

Such comments fueled speculations that Pyongyang may test-fire a long-range rocket, which South Korea claimed was a ballistic missile, around the upcoming Oct 10 grand celebrations.

The DPRK recently erected a 67-meter-long launch tower for long- range rockets, taller than the previous 50-meter pad, at a Tongchang-ri rocket base in the northwest DPRK. The country fired a three-stage Unha-3 rocket into the space orbit in December 2012, two months before its third nuclear test.

Pyongyang's planned rocket launch comes after marathon talks between top military officials of the two Koreas late last month that resulted in a Aug. 25 agreement.

Under the agreement, the two sides promised to lower military tensions and hold inter-governmental dialogues in Seoul or Pyongyang at an earliest possible date.

The ROK and the DPRK already agreed to hold the reunion of families, separated by the 1950-53 Korean War, from Oct 20 to 26 in the scenic Mount Kumgang resort in the southeastern DPRK.

Despite uncertainties over the DPRK's rocket firing, Red Cross officials of the two Koreas exchanged the short list of the separated families as planned to verify the willingness to participate in the humanitarian event and confirm whether the families are still alive.

Meanwhile, an unnamed director of the DPRK's Atomic Energy Institute was quoted by the KCNA news agency as saying Tuesday that its scientists were "steadily improving the level of nuclear weapons" in quality and quantity.

If the United States and other hostile forces persistently seek reckless hostile policy towards the DPRK, Pyongyang is "fully ready to cope with them with nuclear weapons any time, the director said.

He noted that all the nuclear facilities around Yongbyon, a city about 100 km northeast of the capital Pyongyang, were re- arranged, changed or re-adjusted to start normal operations as announced by the DPRK in April 2013. The facilities included the uranium enrichment plant and the graphite-moderated reactor.

Cheong Seong-chang, senior analyst at the private Sejong Institute, said by phone that possibility became higher for the DPRK to conduct its fourth nuclear test, noting that it would lead to very unstable security conditions on the peninsula.

The analyst urged the South Korean government to offer to the DPRK holding the top-level inter-Korean dialogue, the same as the talks held in late August, to encourage the DPRK to drop a plan for the long-range rocket launch.