North Korea increased activity at its main underground nuclear test site shortly after officials there reaffirmed that they would expand their nuclear arsenal, a research group that studies the isolated country said Thursday.
A report from the U.S.-Korea Institute at Johns Hopkins School of Advanced International Studies in Washington, D.C. details work at the site in the northeastern area of Punggye-ri. Scholars at the institute studied commercial satellite images of the site. The images indicated new tunnels being dug, possibly for future tests, the New York Times reports. But despite the uptick in activity, the report said there is no sign a nuclear test is imminent.
On Wednesday, North Korea’s Foreign Ministry reaffirmed it would expand its nuclear arsenal to counter what it says are threats of U.S. hostility. A foreign ministry spokesman was quoted by Korean English-Language channel Arirang News saying, “We will not be tied down by anyone.”