"This would be the biggest undertaking by the worldwide community when it comes to denuclearization or disarmament", said Olli Heinonen, an arms control expert at the Foundation for Defense of Democracies, a national security think-tank.
"I appreciate Kim Jong-un doing this and allowing them to go", Mr Trump said.
In recent months, increased tensions over North Korea's nuclear and ballistic missile programs led to a barrage of insults between Trump and North Korean leader Kim Jong Un as the two openly threatened war.
The test tunnels will be blown up, blocking their entry points, while observation facilities and research institutes will be removed along with guards and researchers, the statement said.
"If North Korea takes bold action to quickly denuclearize, the United States is prepared to work with North Korea to achieve prosperity on the par with our South Korean friends".
Kim and President Donald Trump will meet in Singapore on 12 June.
A series of U.S. administrations have sent envoys, both official and unofficial, to Pyongyang in the hope of stopping North Korea's nuclear weapons program.
He had written in a tweet on April 30: "Numerous countries are being considered for the peace, but would Peace House/Freedom House, on the Border of North and South Korea, be a more representative, important and lasting site than a third party country?"
North Korea has yet to publicly comment on the matter.
Unification Ministry spokesman Baik Tae-hyun did not provide a clear answer on whether the women could be returned to North Korea if it's confirmed they didn't want to come to South Korea.
Fox News reported that the summit is expected to take place in Singapore in early June. "It wasn't a question of relying on global mechanisms". "It would have taken them about five years to produce enough material for one weapon", Heinonen said. Ensuring that North Korea lives up to its commitment to give up its nuclear weapons will be far more hard than it sounds, given that it would probably require the sort of onerous and highly invasive inspection regime - with access to previously secret sites - that North Korea has resisted in the past.
Several years later Libyan leader Moammar Gadhafi was removed from power by rebels backed by North Atlantic Treaty Organisation air support.
The move was widely seen as a power play by Kim, the third and youngest of his family to rule the country.
Nearby Mongolia was also ruled out as a possible neutral third-country venue, reportedly for security reasons. The man, who's now also in South Korea, said he carried out the escape under plans arranged by South Korea's National Intelligence Service and that the women were brought along without knowledge of where they were going.
Vice President Mike Pence says North Korea has been dealing with the U.S.
"We studied the nuclear test that occurred September 3 in North Korea using space data and found the whole mountain edifice, Punggye-ri, collapsed and is likely nonusable for further tests", said Sylvain Barbot, professor of Earth sciences at USC Dornsife.
Referring to the 6-party talks on the North's nuclear issue, which have been suspended since 2008, it said Japan disrupted efforts made within the multilateral diplomatic framework 10 years ago by raising that issue.
Taking this into account, he will likely look to one specific agreement that the United States holds sacrosanct, the Nuclear Non-Proliferation Treaty (NPT).
"You need to dismantle in such a way that you can not restore the activity", Heinonen said.