Experts say this is the first time a North Korean leader has made a direct address to an global audience - and it merits serious and thorough consideration.
On Thursday, US President Donald Trump ordered new sanctions that open the door wider to blacklisting people and entities doing business with the isolated nation, including its shipping and trade networks, further tightening the screws on Pyongyang's missile programme.
China wants to stop North Korea's nuclear and missile development but has warned against pushing the government of Kim Jong Un so hard it collapses, or hurting ordinary North Koreans.
A 3.4 magnitude natural disaster has been detected in North Korea amid fears of ANOTHER nuclear test.
North Korea says it needs to have a nuclear deterrent because the United States intends to invade it. Analysts say the North is likely to soon achieve its objective of possessing nuclear missiles capable of reaching any part of the US homeland.
"The United States has great strength and patience, but if it is forced to defend itself or its allies, we will have no choice but to totally destroy North Korea", Trump said at the United Nations General Assembly Tuesday.
Leader Kim Jong Un did not specify what action he would take against the USA or Trump, whom he called a "mentally deranged U.S. dotard" in the latest bout of insults the two leaders have traded in recent weeks.More news: Korea Threatens Nuclear Bomb Test Over Pacific Ocean After Trump's UN Speech
More news: Strong 6.2 magnitude quake shakes central Mexico
More news: 3.5-magnitude quake hits North Korea near nuclear test site
North Korea's Foreign Minister Ri Yong Ho, now in NY for a United Nations meeting, warned on Thursday that Kim could consider a hydrogen bomb test of an unprecedented scale over the Pacific.
"This event occurred in the area of the previous North Korean nuclear tests", the USGS said.
However, South Korea's state weather agency says there is insufficient ground to assume today's quake in the North to be linked to another missile test.
Media captionHow would war with North Korea unfold?
North Korea's weakest nuclear test, its first one, conducted in 2006, generated a magnitude 4.3 quake. In recent months, it has also launched a pair of still-developmental ICBMs it said were capable of striking the continental United States and two intermediate-range missiles that soared over Japanese territory.
"I will surely and definitely tame the mentally deranged U.S. dotard with fire", Jong-un was quoted as saying by state-run KCNA news agency.
"The Chinese authority announced the measures to implement the U.N. Security Council resolution approved on September 11", a diplomatic source in Beijing said.
Trump's executive order expanded the Treasury Department's ability to target anyone conducting significant trade in goods, services or technology with North Korea, and to ban them from interacting with the USA financial system. "Unless the DPRK believes that the benefits from trade with the global community are greater than the current security benefits of prioritizing its military-first economy, North Korea will have little incentive to change its policy".