SEOUL, Jan. 27 (UPI) -- North Korea is prepared to launch a long-range missile at any time in the wake of its fourth nuclear test, officials in Seoul said.
A source at Seoul's spy agency who spoke to Yonhap on the condition of anonymity said Thursday ongoing movement has been detected in Tongchang-ri, North Pyongan province, in and around the North's Sohae Satellite Launching Station.
Last August, satellite images showed North Korea had placed a large roof over a rocket-launching platform, the same platform from where in 2012 North Korea launched the expandable carrier rocket Unha-3 that fell into the Yellow Sea.
The debris of a second stage launch fell into the Philippine Sea after an object had entered orbit.
The source said Seoul believes a "surprise launch" could happen anytime, due to the preparations evident in satellite images.
In a separate report Japanese news agency Kyodo quoted an unidentified Japanese official who said there are signs of North Korean preparations for a missile launch in Tongchang-ri – an observation that was also based on satellite imagery.
The reports of North Korea readiness comes a day after U.S. Secretary of State John Kerry could not obtain an agreement from Beijing to toughen sanctions against North Korea.
China is committed to denuclearization on the Korean peninsula but other values, including "the commitment to uphold peace and stability, the commitment to resolve the issue through dialogue and consultation" are equally important, Chinese Foreign Minister Wang Yi said.
China is concerned sanctions could accelerate a North Korea collapse that would then lead to a refugee crisis at its border.
On Thursday officials at South Korea's presidential Blue House did not confirm either of the reports, South Korean news service News 1 reported.