SEOUL, March 14 (UPI) -- North Korea continues to claim that it is capable of "miniaturizing" its nuclear weapons as it threatens the South, but Seoul's military and intelligence sources said Pyongyang does not have the capability.
South Korea's Defense Ministry spokesman Moon Sang-kyun said Monday during a regular press briefing that Seoul does not believe North Korea has reached a stage where nuclear weapons can be mounted on ballistic missiles, local outlet Newsis reported.
"North Korea has reached a significant level of progress ... but it still has not been able to secure a miniaturized nuclear warhead," Moon said.
The spokesman's answer was a follow-up to a question from a reporter regarding the statements from Jeffrey Lewis of the James Martin Center for Nonproliferation Studies, published on the Johns Hopkins website 38 North.
Lewis had written that there is "enough open source evidence to take seriously the possibility that North Korea has developed a compact fission device that is approximately 60 cm in diameter and weighs between 200-300 kilograms."
But neither U.S. nor South Korea intelligence agreed with these claims, and Seoul is calling Pyongyang's bluff.
The North Korea-issued statement is mostly for propaganda purposes and internal use, experts say.
Pyongyang's weapons claims have been accompanied by strong condemnations of the U.S.-South Korea joint exercises that are ongoing.
The exercises Key Resolve and Foal Eagle are to be held until April. They are the largest-ever joint U.S.-South Korea military exercises and include 17,000 U.S. troops and 300,000 South Korean soldiers.
In an extensive feature piece in the North's Rodong Sinmun, the state newspaper, Pyongyang said it would respond with its own training exercises in preparation for "liberation" of the South and Seoul.