A satellite image taken last April of North Korea's Punggye-ri Nuclear Test Site. Photo: Airbus Defense & Space and 38 North via AFP

Commercial satellite imagery of North Korea’s Punggye-ri Nuclear Test Site from mid-March hints a significant slowdown in tunneling has occurred, according to analysis posted on Friday by 38 North.

The Johns Hopkins University specialist website on North Korea says the reduced activity coincided with a period when high-level talks between North and South Korea moved forward, including Pyongyang’s proposal for a summit with US President Donald Trump. This is being taken as a sign that the North is honoring its pledge not to conduct further nuclear or missile tests prior to a planned summit between Trump and leader Kim Jong-un by May.

Analysts Frank V. Pabian, Joseph S. Bermudez Jr. and Jack Liu say the photos also show a reduced presence of related personnel at the test site when compared to two weeks earlier.

“Imagery from early March had shown signs of continued tunneling excavations at the West Portal, including mining carts and significant amounts of new spoil deposits. Large groups of personnel were also noted in the open support areas serving the nuclear test site’s Command Center,” the analysts wrote. “However, imagery from March 17 showed no evidence of tunneling operations or the presence of any personnel or vehicles at any of the support areas including those near the Command Center.”

The analysts called the slowdown an important development given efforts to establish high-level meetings between the US and the two Koreas. “However, whether this is just a temporary development or whether it will continue over time is unclear,” they concluded.