The U.N. Security Council will "almost automatically" seek a resolution calling for harsher sanctions on North Korea should it conduct another nuclear test, a top South Korean envoy to the United Nations said Thursday.

During a meeting with local reporters here, Ambassador Oh Joon warned that though the latest package of UNSC sanctions on the North are touted as the harshest in decades, the sanctions could be further tightened if there is another major provocation.

"The UNSC would automatically discuss (sanctions) should there be another nuclear test or long-range missile test," the ambassador said, referring to the "trigger clause" that ensures the UNSC takes immediate steps in response to more Pyongyang provocations.

Pyongyang has been escalating its threats against Seoul and Washington in response to the allies' ongoing military drills and the recent adoption of the UNSC sanctions resolution to punish the North's nuclear test in January and rocket launch in February.

Earlier this week, the reclusive state even threatened to conduct a new "nuclear warhead explosion test" and ballistic missile tests "in a short time," further heightening cross-border tensions.

Underscoring that the North has diverted its scarce resources to its expensive pursuit of nuclear arms and missiles, Oh said Pyongyang's provocative behavior had affected major countries' desires to help address the humanitarian concerns facing North Koreans.

"The U.N. has an annual target budget of $100 million or $200 million for humanitarian assistance to the North," he said. "But less than half the target has been achieved, with many contributors feeling cautious about helping the North that is under U.N. sanctions and is constantly challenging UNSC decisions."

Oh added that the international community's concerns about Pyongyang's diversion of resources for military purposes has been clearly expressed in the latest UNSC resolution that points out North Koreans have "great unmet needs."

The envoy said that the livelihoods of North Koreans would improve should the North stop its nuclear and missile programs, for which it is thought to have spent some $4 billion so far. (Yonhap)