A report issued Thursday by 38 North says the activity - spotted in satellite images taken last month - underscores Pyongyang's efforts to maintain the site despite news that tunnel collapses killed several hundred people there after its sixth and most powerful nuclear test on September 3.
"Approximately nine mining carts are present at the West Portal, and there appear to be new rails on top of the spoil pile", 38North experts said in a report.
"Nuclear weapons must be banned", Francis said, quoting a document issued by Pope John XXIII at the height of the Cold War and adding that there is "no denying that the conflagration could be started by some chance and unforeseen circumstance".
But diplomats also said they are not completely knowledgeable of how North Korea could achieve nuclear parity with a powerful United States. "I think you people are surprised".
"I don't want to comment on it", Trump told The Wall Street Journal after he was asked directly if he had spoken with Kim. "I just don't want to comment". Seoul and Washington have also agreed to postpone joint military drills until after the games, which Trump said "sends a good message to North Korea".
There has been a possible thawing in tensions on the peninsula after officials from the two nations met face to face on Tuesday for the first time in more than two years in the border town of Panmunjom, known as "truce village", in the Korean peninsula's heavily fortified demilitarised zone.
In a story posted on the North Korea analysis website 38 North, Alexander Vorontsov, the head of the Institute of Oriental Studies of the Russia Academy of Sciences, conveyed the unstable North Korean atmosphere based on a trip to Pyongyang in mid-November that lasted several days and his conversations with foreign ministry officials there.
"Y$3 ou see that a lot with me and then all of a sudden somebody's my best friend", Trump said. You could give me 30.
Yonhap reported Thursday North Korea's religious council strongly condemned a U.S. State Department designation of the regime as a country of particular concern under the International Religious Freedom Act. "I'm a very flexible person".
Trump's strategy with North Korea has been hot and cold.
Tunneling activities at North Korea's main nuclear test site have been stepped up, a US -based think tank said Thursday, even as the inter-Korean peace talks resumed over the past week.