Arms control experts estimate that the dismantlement of North Korea’s nuclear program could take a decade to complete, and cost $20 billion, if a nuclear agreement is reached between U.S. President Donald Trump and North Korean leader Kim Jong Un when they meet in Singapore on June 12, VOA reported.

“The hard work has not yet begun, and it is gong to take sustained energy on the part of the United States, South Korea, Japan, China and North Korea. It’s going to be a multiyear long process,” said Daryl Kimball, the executive director of the Arms Control Association in Washington.

North Korea is estimated to have 20 to 80 nuclear warheads, both known and covert nuclear research and processing sites, and thousands of ballistic missiles that can be launched from mobile vehicles, and submarine based launchers have been tested in recent years.

With such an extensive nuclear arsenal it could cost $20 billion to achieve the U.S. goal of complete, irreversible, and verifiable nuclear dismantlement (CVID), according to a recent study conducted by Kwon Hyuk-chul, a Kookmin University professor of security strategy.