Any diplomatic agreement in which North Korea agreed to give up its nuclear weapons could take as long as 10 years to implement, according to a new analysis from former US officials.
The assessment, released Monday by experts at Stanford University, comes as the White House is trying to verify how committed North Korea is to denuclearization and how it could be achieved, ahead of a potential summit between the two leaders.
Siegfried Hecker, a respected nuclear scientist who has previously traveled to North Korea to inspect its nuclear site, co-authored the roadmap with Robert Carlin, a Korea analyst who spent years at the CIA and State Department, and Elliot Serbin, Hecker's research assistant.
The trio identified 22 specific programs or activities -- such as the country's nuclear weapons stockpile, its missile arsenal or its nuclear reprocessing facilities -- that US negotiators need to address with North Korea. Halting or suspending many of these will likely take less than a year, the authors estimate, but eliminating or setting limits on them will take six to 10 years.
Last week, US President Donald Trump abruptly canceled his planned Singapore summit with North Korean leader Kim Jong Un, in part due to concerns on whether Pyongyang was willing to agree to what's known as CVID -- complete, verifiable and irreversible dismantlement of the country's nuclear program.
After a flurry of diplomatic activity, Trump has hinted that the talks may be back on. US officials are in Singapore and South Korea to prepare for the summit's potential revival.
Sung Kim, the US envoy to the Philippines and a former ambassador to South Korea; Randall G. Schriver, the assistant secretary of Defense for Asian and Pacific Security Affairs; and Allison Hooker, director for Korea on the White House's National Security Council, traveled to North Korea Sunday and held talks with their counterparts.
Talks could potentially resume Wednesday at the demilitarized zone that divides the two Koreas, a person familiar with North Korea-US relations told CNN.
"The goal here is to create an environment where North Korea would not desire nuclear weapons development by removing the threat perception (posed by the United States)," said Chun Yung-woo, a former South Korean national security adviser.
Some of Washington's top officials working on North Korea -- including national security adviser John Bolton and Susan Thornton, the State Department's acting ambassador for East Asia and Pacific affairs -- have said publicly that Trump will seek a deal that involves North Korea rapidly denuclearizing. Thornton likened it to a large down payment at an event sponsored by The Wall Street Journal in Japan.
Analysts and weapons experts have been quick to point out that an agreement on denuclearization would take a significant amount of time, due to the complexity of the negotiations and the lack of trust between the two sides.
But the authors of the study say time is also needed to assuage North Korea's security concerns. Hecker, who previously served as the director of the Los Alamos National Laboratory, told The New York Times he believes it could take as long as 15 years, given the uncertainties in the process.
"Such assurance cannot be achieved simply by an American promise or an agreement on paper, it will require a substantial period of coexistence and interdependence," the study concluded.