According to 38 North, a US-based North Korea watchdog site, photos taken on April 25 of the Punggye-ri nuclear test site show that water pumping from the area at the facility’s north portal, where the tests typically take place, has resumed, in order "to maintain an optimal environment for instrumentation and stemming." This may be so that communications or monitoring equipment can sit on dry land.
The site also noted an unusually high number of personnel at the facility, and suggested that Pyongyang may just be putting on a show in response to media attention around their ballistic missile and nuclear weapons programs.
"Based on satellite imagery alone, it is unclear if this activity indicates that a nuclear test has been cancelled, the facility is in stand-by mode or that a test is imminent. The presence of a large number of people dispersed throughout the facility in the latest image, however, is unusual and almost assuredly a component of an overall North Korean deception and propaganda effort," the analysis reads. It adds that personnel seemed to be engaged in games of volleyball at different locations at the site.
Pyongyang said on Monday that they would carry out their next nuclear test whenever and wherever leadership deemed it appropriate, and that it was building up its "pre-emptive nuclear attack" capabilities. This comes amid ongoing saber rattling between North Korea and the US, as Washington continues its annual joint military drills with South Korea, and has positioned both a Navy carrier strike group and a nuclear powered submarine near the Korean Peninsula.
North Korea is said to be developing a missile capable of reaching the US mainland, and has conducted five nuclear tests in the past 11 years.
US President Donald Trump has said he would be “honored” to meet with North Korean leader Kim Jong-un under certain circumstances, though he was vague on the details.