The concern was testing ICBM's that could reach America. Those were stopped as were nuclear tests, both because of Trump making a deal with them.
On July 4, 2017, North Korea tested their first ICBM and conducted additional ICBM tests thru November. They already have ICBMs capable of reaching the United States as well as nuclear warheads. Now they are working on expanding their options into submarine launched missiles and multiple warhead delivery capability.
In October 2019,
North Korea walked out on further negotiations and successfully tested a new submarine launched intermediate-range ballistic missile which makes for a deadly mobile launch platform. *"Preliminary analyses of Pukguksong-3’s trajectory estimate its range at roughly 1,900 km (1,1180 miles)."
https://www.brookings.edu/blog/order-from-chaos/2019/10/18/why-north-korea-walked-away-from-negotiations-in-swedenKim Jong Un has several reasons for thinking his latest gamble to pressure Washington will pay off.
First, Kim has been emboldened by the president’s comments since the two leaders’ first summit in Singapore. Trump has said, among other things, that he has fallen “in love” with Kim, admired Kim’s autocratic behavior, absolved Kim of his role in the torture and death of U.S. college student Otto Warmbier, agreed with the dictator that U.S.—South Korea military exercises are “ridiculous and expensive,” and dismissed the slew of short-range ballistic missiles as being “very standard” and “not a violation of our signed Singapore agreement.”
Based on the president’s positive comments — and apparent disregard for the security concerns of U.S. allies —
Kim was unafraid to test what Pentagon officials said was a short- to medium-range ballistic missile from a sea-based platform, reinforcing experts’ fears that the regime is making significant progress in missile-related technologies even as Kim is writing “beautiful” letters to Trump. Other reports and expert analysis have pointed to North Korea’s likely ongoing production of fissile material for nuclear weapons, improvements in the reliability of its short-range missiles, increased training exercises, and efforts to undermine missile defenses in the region.
Kim’s weapons are now more mobile, more reliable, more diverse, and more dangerous.*https://missilethreat.csis.org/missile/pukguksong-3/In October 2020, North Korea revealed a much larger ICBM during a military parade.
North Korea has unveiled a new ballistic missile whose "colossal" size has surprised even seasoned analysts of the country's arsenal.https://www.bbc.com/news/world-asia-North Korea: What we know about the 'massive' new missileThis new ICBM is Mr Kim's promised strategic weapon.
It absolutely targets the US, and is delivered as a fait accompli in the face of failed negotiations with the Trump administration.
North Korea already has two tested ICBMs. The Hwasong-14 was tested twice in 2017 and with a range of 10,000km (6,213 miles) can reach nearly all of western Europe and about half of the US mainland carrying a single nuclear warhead.
The Hwasong-15, also tested in 2017, has a range of 13,000km, meaning it can deliver a single nuclear warhead anywhere in the US mainland.The new ICBM, which has yet to be tested, is also a two-stage liquid-fuelled missile, but with a greater length and diameter than the Hwasong-15. Until the engines are revealed or a test is carried out, it is unlikely we will know its exact range.
However,
the design makes North Korea's intentions very clear: they do not need to increase the range of their missiles anymore.Instead, they are focusing on trying to launch multiple nuclear warheads on a single missile. This would be yet another blow to the already struggling US missile defence systems, because for each incoming warhead, multiple interceptors need to be launched.
On January 14, 2021 in the final week of Trump's presidency, North Korea displayed a new submarine launched missile.
https://www.bbc.com/news/world-asia-North Korea unveils new submarine-launched missileAnalysts noted it was a previously unseen weapon. "New year, new Pukguksong," tweeted North Korea expert Ankit Panda, using the North Korean name for their submarine-launched ballistic missiles (SLBMs).
"The world's most powerful weapon, submarine-launch ballistic missiles, entered the square one after another, powerfully demonstrating the might of the revolutionary armed forces,"
the official Korean Central News Agency said."They'd like us to notice that they're getting more proficient with larger solid rocket boosters," Mr Panda tweeted, noting what appeared to be new solid-fuel short-range ballistic missiles on display too. These missiles can be launched more quickly than liquid-fuelled varieties.
Over the last four years, Pyongyang has had an erratic relationship with the US under President Donald Trump's administration. Mr Kim and Mr Trump engaged in mutual insults and threats of war before an unprecedented summit in Singapore in 2018 and declarations of love by the outgoing US leader.
Despite the apparent warming of relations, little concrete progress was made on negotiations over North Korea's nuclear programme and a second summit in Hanoi in 2019 broke down after the US refused Pyongyang's demands for sanctions relief.
Hey—Despite all of your bragging, thanks for nothin' Donnie.
