WASHINGTON, May 5. /TASS/. North Korea has built several facilities at the Punggye-ri nuclear test site, destroyed in 2018, participants of the Beyond Parallel project of the US Center for Strategic and International Studies said.

According to them, satellite imagery of the Punggye-ri Nuclear Test Facility made on April 21 "shows new activity at the site." One image reveals that the road leading to the collapsed portal for Tunnel No. 4 has been built, and "two new small buildings" have recently been constructed in front of it. Another shows cables running from the two nearby structures into another portal.

"Although the recently observed activity is not a strong indication of imminent testing, the long-anticipated seventh nuclear test will almost assuredly take place at the Punggye-ri Nuclear Test Facility," the US experts said.

South Korea has been strengthening its monitoring of North Korea's Punggye-ri nuclear test site, the Yonhap news agency said. Views on the timing of the North's nuclear test vary, the agency reported. Some experts said the North "may not conduct a test anytime soon given that it appears to have acquired enough technologies through six nuclear tests," while others said "the regime might see a technological imperative to refine technologies for tactical and other nuclear weapons."

In February 2005, the DPRK declared that it possessed nuclear weapons "intended solely for self-defense and deterrence." On October 9, 2006 it conducted its first underground nuclear test at the Punggye-ri test site in Hamgyong-bukto province (according to Western estimates, its yield was less than one kiloton of TNT). Five more tests followed. The fourth and sixth tests were thermonuclear, Pyongyang said.

In 2018, North Korea announced that it would dismantle the test site. The North Korean authorities exploded its tunnels and buildings in the presence of foreign journalists.