The country’s central news agency said tunnels will be collapsed with explosions, blocking entrances, while observation facilities, research buildings and security posts will be closed.
The event, which journalists across the world including from America and South Korea will be invited to cover, will take place between May 23 and May 25, depending on weather.
The news came as Mike Pompeo, the US secretary of state, said America was prepared to help the regime boom economically if it denuclearises.
The developments precede Donald Trump’s historic meeting with Kim Jong-un, the North Korean leader, scheduled for June 12 in Singapore.
David Beasley, executive director of the UN’s World Food Programme, said on Saturday that he believed North Korean leaders wanted change after a four-day visit to the country.
He told BBC Radio 4’s Today programme: “We must capture this moment and work diligently to move the ball forward down the road toward progress and peace.
“And I am hopeful. I do believe there’s a genuine desire to move forward, but time will tell.”
Mr Pompeo, who has visited North Korea twice in recent weeks, said the country could have a bright economic future if it quickly agrees to give up its nuclear weapons.
If North Korea took “bold action” to quickly denuclearise, then the US was prepared to reward Pyongyang by propelling it towards the same levels of prosperity as the neighbouring South, he said at a press conference in Washington.
“If Chairman Kim chooses the right path, there is a future brimming with peace and prosperity for the North Korean people,” Mr Pompeo added.
His comments set a positive tone for the talks in the Asian city-state of Singapore on June 12, and follow a goodwill gesture from Pyongyang after Kim agreed last week to release three Americans who had been held prisoner for over a year.
Lee Hsien Loong, the Singaporean prime minister, has hailed the decision to hold the “historic and momentous event” in his tiny nation, and the news has been largely welcomed by the public, despite concerns over tight security, roadblocks and traffic chaos on the 85-mile long island.
The local media has already touted several possible venues for the high stakes meeting, including the glitzy Marina Bay Sands hotel and casino resort, which is owned by Sheldon Adelson, an American business magnate and one of the largest donors to the Republican party.
However, the luxury five-star Shangri-la hotel, a short distance from Singapore’s main shopping boulevard, is “on top of the list” of likely locations for the meeting, said Toby Koh, group managing director of Ademco Security.
The hotel has hosted annual meetings of defence ministers and military chiefs since 2002 and its security procedures were “down pat,” said Mr Koh.
“They don’t really need to do a lot more to improve it.” But the luxurious settings that Singapore has to offer will do little to detract from the difficulty of the negotiations that the two leaders face.
In spite of easing tensions in recent months, Pyongyang has given few indications of being willing to go beyond sweeping statements in support of the concept of denuclearisation.
Washington, meanwhile, remains committed to the “complete, verifiable and irreversible dismantlement” of North Korea’s nuclear programme.
Nevertheless, Mr Pompeo described his meeting with Kim last week in Pyongyang as “warm” as they communicated “mutual objectives.”
“We talked about the fact that America has often in history had adversaries who we are now close partners with and our hope that we can achieve the same with respect to North Korea,” he said.