Kim Jong Un's nuclear ambitions could be "catastrophic for the world", the UK warned, as the United Nations Security Council backed an escalation of sanctions against Pyongyang.
The UK ambassador to the UN, Matthew Rycroft, said North Korea's development of intercontinental ballistic missiles (ICBMs) had significantly extended the threat posed by the secretive regime.
Calling on North Korea to "halt and reverse" its nuclear and missile development programmes, Mr Rycroft said the country should "forgo the path of provocation".
He said: "North Korea bears full responsibility for the measures we have enacted today. By acting in flagrant violation of its legal obligations, by going against the will of the Security Council expressed in countless resolutions, North Korea has chosen the path it now finds itself on.
"It is a path that, at a minimum, will lead to further suffering for its own people and at most could prove to be catastrophic for the whole world.
"It does not have to be this way. North Korea should forgo the path of provocation, forgo the path of further escalation."
At a meeting in New York the Security Council unanimously approved new sanctions including banning exports worth over a billion US dollars (£770 million).
The resolution also bans countries from giving any additional permits to North Korean workers - a crucial source of foreign currency for the regime but a situation labelled "a form of modern slavery" by Mr Rycroft.
The sanctions follow North Korea's first successful tests of ICBMs capable of reaching the United States last month.
The resolution bans North Korea from exporting coal, iron ore, lead and seafood products - the "lifeline exports that sustain Kim Jong Un's deadly aspirations", Mr Rycroft said.
He added: "North Korea is no longer a threat faced by a single country or a single region. It is instead a threat that confronts us all."
He said as the regime's missile capabilities advanced "so too does their contempt and disregard for this Security Council".
"We must meet this belligerence with clear, unequivocal condemnation and with clear, unequivocal consequences."
The resolution, drafted by the US but negotiated with North Korea's neighbour and ally China, is aimed at increasing economic pressure on Pyongyang to return to negotiations on its nuclear and missile programmes.
US ambassador to the UN Nikki Haley said: "The price the North Korean leadership will pay for its continued nuclear and missile development will be the loss of one third of its export and hard currency.
"This is the most stringent set of sanctions on any country in a generation."
Foreign Office Minister Lord Ahmad of Wimbledon said: "The UK and our international partners are united in opposing and standing firm against the threat posed by North Korea.
"This resolution will cut the resources that North Korea is abusing to fund its reckless and illegal pursuit of nuclear and ballistic missile programmes.
"North Korea has chosen this extremely dangerous and destabilising path. The regime is prioritising the pursuit of these weapons over and above its people, peace and stability in the region.
"The North Korean regime needs to change its course immediately and the UK calls on all countries to implement these new measures fully and robustly."