SEOUL • Activity has been detected at North Korea's main nuclear site, suggesting that Pyongyang may be reprocessing radioactive material into bomb fuel since the collapse of a summit with Washington, according to a United States monitor.
The possible signs of fresh reprocessing activity last week come after a February summit between US President Donald Trump and North Korean leader Kim Jong Un ended abruptly in Hanoi without agreement on Pyongyang's nuclear programme.
Since then, North Korea has said it was mulling over options for its diplomacy with the United States and Mr Kim said last week that he was open to talks with Mr Trump only if Washington came with the "proper attitude".
The Centre for Strategic and International Studies said yesterday that satellite imagery of the Yongbyon nuclear site on April 12 showed five railcars near its uranium enrichment facility and radiochemistry laboratory.
"In the past, these specialised railcars appear to have been associated with the movement of radioactive material or reprocessing campaigns," the Washington-based monitor said.
"The current activity, along with their configurations, does not rule out their possible involvement in such activity, either before or after a reprocessing campaign."
Mr Trump and Mr Kim held their first landmark summit last June in Singapore, where the North Korean leader signed a vaguely-worded deal on the "denuclearisation of the Korean peninsula".
But their failure to reach agreement at their second summit in Hanoi on walking back Pyongyang's nuclear programme in exchange for relaxation of sanctions has raised questions over the future of the wider process.
The US President walked away from a partial deal proposed by Mr Kim which included an offer to dismantle the Yongbyon complex.
About 100km north of Pyongyang, Yongbyon is home to the country's first nuclear reactor, and is the only known source of plutonium for the North's weapons programme.
Yongbyon is not believed to be the North's only uranium enrichment facility and closing it down would not in and of itself signal an end to the country's atomic programme.
North Korea suspended nuclear and missile testing during the diplomatic process last year, but the International Atomic Energy Agency has said there were indications that Yongbyon has been in use as recently as the end of February.
The US special envoy for North Korea was due in Moscow yesterday as the Kremlin said it was preparing for possible talks between Russian President Vladimir Putin and Mr Kim.
Media reports said the first summit between the two leaders could come as early as next week.
"Active preparations for a potential meeting are under way," Russian presidential aide Yuri Ushakov said in comments reported by news agencies. But he would not be drawn on the location or date of a potential summit.
The US State Department said Mr Stephen Biegun would be in Moscow yesterday and today "to meet Russian officials to discuss efforts to advance the final, fully verified denuclearisation of North Korea".
Quoting diplomatic sources, Russian newspaper Izvestia reported that the meeting would take place in Vladivostok before the Russian leader heads to China for an April 26-27 summit.
Russia is keen to play a stronger role in international talks over North Korea's nuclear programme.
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