North Korea has been engaging in major deception by offering to dismantle a launching site at the same time it secretly continues to make improvements at 16 hidden bases that would bolster launches of conventional and nuclear warheads, The New York Times reported on Monday.
The bases, which are scattered across the country, are located in underground facilities tunneled in narrow mountain valleys, according to the researchers. Western experts eventually concluded that Pyongyang now has the ability to hit most of the United States, although it remains unclear if it could produce a nuclear weapon small enough to fit atop a missile.
After the landmark summit in Singapore, Trump tweeted that "there is no longer a Nuclear Threat from North Korea".
The revelation appears to undermine North Korea's claims that it is working towards denuclearization and dismantling one of its weapons sites.
But North Korea has stepped up its demands for an easing of U.S. sanctions and the State Department, without offering a reason, said late Tuesday that Pompeo's meeting was off.
While US sanctions on North Korea remain in place, enforcement by traditional trading partners China and Russian Federation has relaxed since the summit, US officials have acknowledged.
Planned talks between US Secretary of State Mike Pompeo and one of Kim's right-hand men, Kim Yong Chol, were also delayed this week.
This prompted North Korea to warn earlier this month that it could even revive its scrapped policy of pyongjin, or "parallel advance", in which the country simultaneously pursues economic and nuclear development, if the its demand is not met.
"What North Korea has offered is the beginning of a process that might - might - someday lead to an outcome like that".
But the vaguely worded deal reached in Singapore - and the resulting stalled denuclearization talks - gave ample ammunition to many critics who pointed to North Korea's long history of obfuscation and outright double-dealing on past agreements.
There have been several recent signs that diplomatic efforts between the United States and North Korea were stalling.
Although the sites are not launch facilities and in some cases are rudimentary, the authors of the report from the Center for Strategic and International Studies say they are hidden and illustrate the scope of the North's weapons program and the country's determination to hide its military might.
At the news conference, Trump pointed out that North Korea has not tested further missiles amid the talks.
Pyongyang may have wanted the missile sites to be seen, suggested David Maxwell, a senior fellow at the Foundation for Defence of Democracies, to keep the pressure on in negotiations.
The South Korean presidential office said that it is sending 20,000 boxes of tangerines in four shipments on Air Force cargo planes over Sunday and Monday.