Foreign and South Korean journalists were on their way on Wednesday to cover the destruction of North Korea's nuclear test site, a gesture of goodwill before a planned historic summit with the USA.
The reporters were invited by Pyongyang. The event is scheduled to take place from Wednesday to Friday.
The North announced last month that it would destroy the site in the north-east by blowing up the access tunnels, an announcement welcomed by Washington and Seoul.
Punggye-ri has so far been the scene of six nuclear tests conducted by Pyongyang. The latest, the most powerful to date, took place in September and is believed to have been a hydrogen bomb.
There was euphoria when the planned summit with the U.S. was announced but since then there have been doubts on both sides. Last week, the North suddenly threatened not to participate and cancelled talks with the South, accusing Washington of wanting to corner it and force it unilaterally to give up its nuclear arsenal. And on Tuesday, it was Donald Trump who raised the possibility of a postponement.
Some experts consider it remarkable that Pyongyang announced the dismantling of the site without asking for anything in return.
Our correspondent in Beijing, NBC's Janis Mackey Frayer, said "North Korea is still likely to go ahead with closing its nuclear site sometime in the next couple of days. South Korean journalists have now joined foreign journalists there, but there are no experts among them, they were not invited to witness it because many of them believe that dismantling the site may destroy valuable evidence."