North Korea appears to have restarted activities at its main plutonium-producing reactor in Yongbyon, the UN atomic agency, IAEA, has said in an annual report. The apparent resumption of operations comes as Pyongyang has been voicing threats to expand its nuclear arsenal amid continued tensions with the United States.

Analysts say cash-strapped Pyongyang is returning to its strategy of trying to obtain concessions from the international community by threatening nuclear proliferation.

North Korea escapee Hiroko Saito says she and 97,000 others were deceived into relocating to the North in the 1960s with promises of "paradise on Earth." Instead, she suffered starvation, repression and loss.

Pyongyang has said it would take action if a new Indo-Pacific alliance between the US, Australia and the UK had "even the smallest negative effect" on North Korea's security.

South Korea has said the North fired an unidentified projectile as Pyongyang's UN envoy defended the rogue country's right to test weapons. North Korea is currently under UN sanctions banning weapons tests.

North Korea's ambassador to the UN tells the General Assembly that "nobody can deny" the nuclear-armed country the right to test weapons. Kim Song's comments at the world body headquarters in New York come just moments after South Korea's military said the North had fired an "unidentified projectile" into the sea off its east coast.

North Korean leader Kim Jong Un said the US is the "root cause" of instability on the Korean Peninsula. He said Pyongyang is only increasing its military capabilities as a deterrent.

The military in South Korea has said the projectile was a submarine-launched ballistic missile. It comes as intelligence chiefs from the US, South Korea and Japan meet in Seoul.

North Korea has confirmed that it tested a new type of submarine-launched ballistic missile on Tuesday, making it the fifth in a round of missile tests by the country since September.

A US envoy said North Korea's recent weapon tests were "concerning and counterproductive." Last week, the isolated nation carried out tests of a new type of ballistic missile launched from submarines.

In a UN Security Council draft resolution, Beijing and Moscow have called for the lifting of trade sanctions on Pyongyang "with the intent of enhancing the livelihood of the civilian population."