SEOUL • South Korea's military yesterday said it was closely monitoring North Korean facilities after a series of satellite images triggered international alarm that Pyongyang might be preparing a long-range missile or space launch.
Analysis indicates increased activity at two key sites - the Samundong missile research facility and the Sohae rocket-testing facility. Any launch could send stuttering talks on denuclearisation into disarray.
South Korea is "closely tracking and looking into all activity for possible scenarios, including a missile launch" across the border, in close coordination with the United States, said Mr Kim Joon-rak, spokesman for the Joint Chiefs of Staff.
Satellite images of Samundong taken late last month showed cars and trucks at the site, as well as rail cars and cranes at a yard, reported US news outlet NPR.
Mr Jeffrey Lewis, a researcher at the Middlebury Institute of International Studies at Monterey, was quoted as saying: "When you put everything together, that's really what it looks like when the North Koreans are in the process of building a rocket."
Located on the outskirts of Pyongyang, the Samundong facility was built in 2012 to support development of long-range missiles and space-launched vehicles.
In addition to developing the Hwasong-15 intercontinental ballistic missile, which analysts agree is capable of reaching the whole US mainland, Samundong constructed the long-range rockets that were then transported and successfully launched from the Sohae satellite launch station in 2012 and 2016.
North Korean leader Kim Jong Un agreed last year to shutter the Sohae site at a summit with the South's President Moon Jae-in in Pyongyang. Satellite pictures in August suggested workers were dismantling an engine test stand at the facility.
But the Washington-based Centre for Strategic and International Studies suggested last week that rebuilding was progressing quickly at the facility.
Respected research website 38 North project said the moving structure that had been used to carry vehicles to a launchpad on rails had been restored. It added that the work had started before last month's failed summit on denuclearisation between Mr Kim and US President Donald Trump.
Mr John Bolton, Mr Trump's national security adviser, said on Sunday the US sees "exactly what they are doing" in regard to possible missile or rocket launch moves by the nuclear-armed state.
"We see it unblinkingly and we don't have any illusions about what those are," he warned, adding that his boss would be pretty disappointed if a nuclear-armed state conducted a new missile test.
North Korea has been banned by the United Nations Security Council from carrying out space launches as some of its technology was similar to that used for intercontinental ballistic missiles.
Since the collapse of the Hanoi summit, Mr Trump has been cautious in his forecasts, continuing to suggest a deal remains possible.
He said Mr Kim promised he would carry out no more missile or nuclear testing, adding: "I take him at his word."