Speaking before the start of a meeting with South Korean Defense Minister Suh Wook at the Pentagon, Esper said: "We agree that North Korea's nuclear and ballistic missile programs remain a serious threat to the security and stability of the region and the world".
Harry Kazianis, senior director of Korean studies at the Center for National Interest, also drew attention to the missile: "What North Korea has shown us, what appears to be a new liquid-fuelled ICBM that seems to be a derivative of what was tested back in late 2017, known as the Hwasong-15, is much bigger and clearly more powerful than anything in the DPRK's arsenal".
As a result of worldwide sanctions to contain Pyongyang's nuclear and missile programmes, China has become North Korea's only real partner.
O'Brien said he did not want to speculate on what would happen if the North resumed its weapons testing, only saying the US appreciates the fact that there have been no such tests for more than two years.
U.S. National Security Adviser Robert O'Brien said Friday that there may be a chance to resume denuclearization talks with North Korea around next summer's Olympic games.
"North Korea tends to ... do something very provocative in the first year of a new US or South Korean administration", he said. Last year, bilateral exchanges with China accounted for 95.4 per cent of North Korea's total trade.
But these improved capabilities only really matter if it survives long enough for the North Koreans to get it in the air.
As for why North Korea made a decision to build a new, even larger liquid-fueled missile, Hanham told Insider that it's a "question that a lot of us our scratching our heads over". Kim Jong Un has called for a "revolution" in reconstructing cities.
If this is proven, this missile system, according to experts, could penetrate United States defenses.
US and North Korea diplomats last met in Sweden in October 2019 for nuclear negotiations, but talks fell through on the first day of discussions.
"Even if the United States were to attempt to build more interceptors to keep up, the costs could be prohibitive", the analysts said.
The missile is carried by a transporter erector launcher with 22 wheels.
"The North Koreans, however, a year ago did exactly zero intercontinental ballistic missile tests".
Once erected, fueling the missile could take hours.
Trump, who is seeking to win a second presidential term in the due date on November 3, boasts that he avoided an all-out war after tension was most intense with Boeing Yang over its missile and nuclear tests.
North Korea is said to be suffering from a triple whammy.