Matthew Rycroft said North Korea’s development of intercontinental ballistic missiles (ICBMs) has significantly extended the threat posed by the secretive regime.
His warning comes as the UN hit the North Korea with new sanctions which would slash North Korea’s £2.29billion ($3billion) annual export revenue by a third.
Mr Rycroft 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.”
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.”
His comments came after the UN’s Security Council unanimously approved new sanctions last night including banning exports worth over £770million ($1billion).
Drafted by the US, the resolution bans North Korean exports of coal, iron, iron ore, lead, lead ore and seafood – the “lifeline exports that sustain Kim Jong–un’s deadly aspirations”.
It also banned countries from giving any additional permits to North Korean workers and adds nine individuals and four entities to the UN blacklist, including North Korea’s primary foreign exchange bank – subjecting them to a global asset freeze and travel ban.
The sanctions follow North Korea’s successful test launch of two ICBMs which experts fear are capable of reaching the US.
Mr Rycroft added as the regime’s missile capabilities advanced “so too does their contempt and disregard for this Security Council”.
He continued: ”We must meet this belligerence with clear, unequivocal condemnation and with clear, unequivocal consequences.”
The sanctions, which were drafted by the US but negotiated with North Korea’s neighbour and ally China, will put pressure on the rogue state in a bid persuade Kim Jong-un’s regime to abandon its nuclear and missile programmes.
US ambassador to the UN Nikki Haley said: “This is the most stringent set of sanctions on any country in a generation.
“We should not fool ourselves into thinking we have solved the problem. Not even close. The North Korean threat has not left us, it is rapidly growing more dangerous.
“Further action is required. The United States is taking and will continue to take prudent defensive measures to protect ourselves and our allies.”