In light of the recent news about North Korea's ballistic missile program, former Central Intelligence Agency director John Brennan says Kim Jong-Un managed to fool Donald Trump during their Singapore summit earlier this year.
He added in his tweet, "I will be the first to let you know if things go bad!"
Pyongyang halted missile and nuclear bomb testing earlier this year but US and South Korean negotiators have yet to elicit from North Korea a concrete declaration of the size or scope of its weapons program me or a promise to stop deploying its existing arsenal.
"In the 2018 New Year address, Kim Jong Un called for shifting to full-scale production and deployment of nuclear weapons and missiles", said Joshua Pollack, a senior research associate at the United States-based James Martin Center for Nonproliferation Studies (CNS).
Experts said the undeclared sites had always been known to USA intelligence agencies but had never been publicly acknowledged by Mr Trump who asserted North Korea was "no longer a nuclear threat" following the June summit.
The New York Times released images from private satellites, reporting that they "suggest" increased ballistic missile development activity at several hidden sites.
North Korea recently warned, however, it could restart its nuclear program if the United States does not drop its campaign of "maximum pressure" and sanctions.
US Secretary of State Mike Pompeo had been scheduled to meet Kim's right-hand man, Kim Yong Chol, in NY last week to discuss denuclearization efforts and prepare for a possible second summit, according to the State Department.
"North Korea has never promised to shut down this missile base", Blue House spokesman Kim Eui-kyeom said.
Marie Harf questioned if North Korea has given anything up, noting that they still have missiles and are just not testing them. The missile bases are home to short range ballistic missiles that threaten US and South Korean forces on the Korean peninsula, medium and intermediate range missile bases that threaten USA bases in the Asia-Pacific and Japan, and intercontinental ballistic missiles that directly threaten the United States. But experts argue that the country hasn't made any commitment to dismantle such missile bases yet, so the fact that it would maintain them doesn't in itself represent a breakdown in talks with the U.S.
Senator Edward Markey, a Massachusetts Democrat who sits on the Foreign Relations Committee, said in a statement that Trump was "getting played by Kim Jong Un".
The report was released less than a week after North Korea abruptly called off a new round of negotiations with Pompeo that had been set for Thursday in NY.
In the speech, however, Kim also hinted at nuclear weapons playing an important role long into the future, calling them a "powerful treasured sword for defending peace" that would "reliably guarantee" a dignified and happy life for generations of North Koreans. On Thursday, Russia called a meeting of the United Nations Security Council to take up its request for humanitarian exemptions to worldwide sanctions on Pyongyang.
The report singled out a base known as Sakkanmol, about 50 miles (80 kilometers) north of the demilitarized zone and one of the closest to South Korea.
Less disputable is that North Korea could quickly assault South Korea, including its capital Seoul, and Japan in a crisis.
The report said the North Korean bases, which can be used to house ballistic missiles of various ranges, are well-hidden, indicating the North's determination to hide its military abilities.