North Korea's National Aerospace Development Administration (NADA) has hinted that Pyongyang may fire a long-range rocket to mark the ruling Workers' Party anniversary in October. The state-run news agency KCNA quoted the director of the country's aerospace organisation as saying that a series of satellites would be launched next month.

"The world will clearly see a series of satellites... soaring into the sky at the times and locations determined by the [Workers' party] central committee... no matter what others might say about it," the unnamed director said.

The launch plan comes after the International Atomic Energy Agency (IAEA) recently said that North Korea had expanded its nuclear facilities. The United Nations organisation said satellite images showed "renovation and construction activities" at the Yongbyon nuclear site.

The director general of the UN agency, Yukiya Amano, was quoted as saying: "Since my last report, we have observed renovation and construction activities at various locations... particularly at the Yongbyon nuclear complex."

The latest developments could see fresh international sanctions being imposed on North Korea. Even as the country, ruled by Kim Jong-un, has been isolated because of its nuclear and other anti-US activities, it has claimed that the rockets to be launched are intended to "put peaceful satellites into orbit".

However, the US and its allies have insisted that North Korea's satellite launches are usually "disguised ballistic missile tests". It is unclear when the satellites would be launched, or whether it would coincide with the ruling party's anniversary, which is on 10 October.

The move could also jeopardise the planned reunion of families separated by the Korean war.