Meanwhile . it appears a North Korean nuclear test may be imminent.
Based on information gathered from recent satellite photos, the U.S.-Korea Institute at the Johns Hopkins School of Advanced International Studies said Friday that North Korea could conduct its third test in the next two weeks.
The institute noted that the North had restored the capability to conduct a nuclear test at its Punggye-ri Nuclear Test Facility, which ran into problems following heavy rains this past summer and fall.
The satellite photos also show a previously unidentified structure, which the think tank believes may be intended to protect data-gathering equipment from inclement weather.
North Korea carried out two previous tests in 2006 and 2009.