South Korea has confirmed that the missile test by North Korea earlier this month has left traces of radioactive gas. However, it could not conclude if this was a test of a hydrogen bomb.
North Korea carried out six nuclear tests on 3 September. This led to the UN Security Council increasing its sanctions against North Korea with the aim of forcing it to run out of fuel and revenue for the programmes it is carrying out.
Meanwhile, North Korea is threatening the US with what it described as the worst pain it has ever suffered, following the imposition of more sanctions.