- 20 updates
North Korea's nuclear threats to the US and its allies are daily and blistering but there is very little substance to them.
There is no evidence Kim Jong-un's country has accurate long range missiles, meaning that the US - and Britain - is not in imminent danger.
However, North Korea does have short and medium range missiles meaning that the threat is real for South Korea.
The Prime Minister said today he was concerned by the increasingly heated rhetoric coming from the Korea Peninsula.
Speaking at a PM Direct event in Glasgow, he said that it is countries like North Korea that necessitate Britain having a nuclear deterrent going forward:
The Prime Minister said that Scotland gains from Britain's membership to international networks such as the Commonwealth, NATO and the EU.
He said it send a wider message that Britain "counts for something in the world".
David Cameron is telling his audience in Glasgow that having the Trident nuclear deterrent is the "best insurance policy that you can have that you will never be subject to nuclear blackmail".
It took three questions to get on to the subject of cuts, with the Prime Minister saying that "defence can't be exempt altogether from difficult decisions".
He says that the new aircraft carriers, Typhoons and other Army kit will be best in the world despite the cuts.
The Prime Minister launched into a brief argument for Scotland remaining as part of the UK after the Scottish referendum in 2014.
He said he believes the case for union can win the "arguments of the heart" as well as the "arguments of the head".
He said he is proud of what the UK has achieved together, such "defeating fascism" and the NHS and BBC.
But he also drew attention to the more than 12,000 people in Scotland employed by the defence industries, which he said were backed by the whole of the UK.
The Prime Minister is hosting a PM Direct event at the factory of a defence contractor in Glasgow.
He opened by praising the "incredible periscope" aboard HMS Victorious - the nuclear submarine he visited earlier - which was manufactured by the firm that is hosting his talk.
The Prime Minister has said that it would be "foolish" for Britain to abandon its Trident nuclear deterrent system in the face of threats from N Korea and other regimes.
Mark Fitzpatrick, Director of Nuclear Non-Proliferation and disarmament, at the International Institute for Strategic Studies believes the David Cameron is "correct" in his assessment.
The Yes campaign for an independent Scotland has tweeted this picture with the caption:
"The amount of money Trident nuclear weapons cost Scotland could pay for 4,500 extra teachers".
Latest ITV News reports
David Cameron said the UK needed to maintain its nuclear deterrent after claiming that North Korea could launch a missile attack on Britain.