"It's hard to say if it happened immediately after the summit and they just rushed everything - I guess it's possible - but it's more likely that it started just before", 38 North Managing Editor Jenny Town told the Washington Post on Wednesday.
"It's too early to see", Trump told reporters in the Oval Office Wednesday afternoon (video below), but noted it's a "very nasty problem". I would be very very disappointed in Chairman Kim.
"This facility had been dormant since August 2018, indicating the current activity is deliberate and purposeful", said researchers at the Washington-based Centre for Strategic and International Studies (CSIS).
"We have to solve a problem".
Yonhap reported Tuesday that work was underway to restore part of the Sohae Satellite Launching Station even as Trump met with Kim at a second summit in Hanoi last week. This could suggest that North Korea was confirming the Tongchang-ri site is a nuclear-related center.
Satellite images seen by 38 North, a Washington-based North Korea project, showed that structures on the Sohae launch pad had been rebuilt sometime between February 16 and March 2, the project's Jenny Town told Reuters.
The pictures show a moving structure that had been used to carry launch vehicles to a launch pad on rails has been restored, it said.More news: Winter Weather Headed Our Way
The IAEA chief said the agency saw indications of ongoing construction work at the light water reactor, adding they also continued to observe signs of the ongoing use of the reported centrifuge enrichment facility. "At the engine test stand, it appears that the engine support structure is being reassembled", the 38 North reported. It said new roofs have been installed on the fuel and oxidizer buildings.
In November of a year ago, Amano said his agency had seen activities consistent with the fabrication of reactor components and the possible transfer of these components into the reactor building.
The nuclear reactor that is believed to have supplied much of the plutonium for North Korea's nuclear weapons appears to have been shut down for the past three months, the United Nations atomic watchdog said on Monday, without suggesting why. He said Kim demanded all sanctions on North Korea end at once in exchange for closing down the Yongbyon nuclear facility.
"The danger here is that we could start spiraling downward as each side takes steps and undermine the process that's been in place since last spring".
After carrying out the third of its three ICBM launches in late 2017, North Korea claimed to be able to attack the mainland United States with nuclear-armed missiles.
There were high expectations for Kim and Trump's second meeting in Hanoi, but no agreement was reached.
U.S. National Security Adviser John Bolton reiterated on Tuesday that North Korea will not "get relief from the crushing economic sanctions that have been imposed on them" unless they dismantle their nuclear weapons program and "everything associated with it".