UN Secretary General Antonio Guterres, in an interview published Sunday, said the showdown over North Korea's nuclear and missile programme was the world's worst crisis "in years" and had left him deeply worried.
"To date, we have had wars which have been initiated after a well thought-out decision," Guterres said in an interview published by the French Sunday newspaper Le Journal du Dimanche.
"But we also know that other conflicts have started through an escalation caused by sleepwalking.
"We have to hope that the seriousness of this threat puts us on the path of reason before it is too late," said Guterres, according to the French language account of the interview.
"It's the most serious (crisis) that we have had to face in years," he said, admitting he was "very worried".
Guterres said the key question was to get North Korea to stop its nuclear and ballistic missile programme and respect UN Security Council resolutions.
"But we must also maintain the unity of the Security Council at all costs, because it is the only tool which can carry out a diplomatic initiative with a chance of success," he said.
The United States wants the Security Council to vote on Monday to impose tougher sanctions against Pyongyang, despite resistance from China and Russia.
A US-presented draft resolution calls for an oil embargo on North Korea, an assets freeze on Kim, a ban on textiles and an end to payments of North Korean guest workers.
Diplomatic sources said Russia and China opposed the measures as a whole, except for the ban on textiles, during a meeting of experts Friday.