Foreign Secretary Boris Johnson has accused North Korea of issuing "blood-curdling threats".
Mr Johnson was speaking to a meeting of the UN Security Council when he called on China and Russia to use their influence to “restrain” the North Korean regime.
He said: "There could hardly be a clearer threat to world peace more demanding of a unified response than the activities of one member of the United Nations, North Korea breaking its treaty obligations, ignoring the will of this council, and making blood-curdling threats to inflict grievous harm on peoples of other countries.
"We urge other partners with direct influence on North Korea to use their leverage to the full with the aim of easing tensions and ensuring compliance with the express will of the UN.
"There is a vital role for China and Russia, both of whom are neighbours of North Korea with influence on Pyongyang, and as permanent members of this council, a special responsibility they have for preserving international peace and security.
"Britain stands alongside our allies in making clear that North Korea must obey the UN and halt its nuclear weapons and ballistic missile programmes - disarming in a complete, verifiable, and irreversible manner."
Mr Johnson said that many countries were not implementing already agreed sanctions against Pyongyang.
"The United Kingdom believes it is vital for this council to stand ready to take further significant measures to bring about a peaceful resolution.
"And sooner or later the North Korean regime must realise that their isolation not only holds back their own people, if the regime really cares about their own people, but also weakens their own grip on power," the Foreign Secretary said.
The UN discussion is happening as the White House has declared that all options, including a targeted military strike, are on the table to prevent North Korea from carrying out threats against the United States and its allies in the region.
US President Donald Trump has said he wants to see a diplomatic resolution to the crisis but fears "we could end up having a major, major conflict".
Reporting by Press Association.