USA experts who analyse satellite images from North Korea say they have seen unusual activity at the country's nuclear site: volleyball games. North Korea says it has already conducted five successful nuclear tests - in 2006, 2009, 2013 and in January and September 2016. The source added that Beijing is also not ruling out the beginning of May as a possible time for a test.
Kim said the DPRK's policy is shaped by the Trump administration's push for "high intensity sanctions" against the country, deploying tactical nuclear weapons in South Korea and launching military action aimed at "beheading" the North's leadership headed by Kim Jong Un.
Although the former military and intelligence officials said they were skeptical that the USA would respond to North Korea's nuclear test with a pre-emptive strike, they said such a response could cause tremendous damage within US -allied countries in the region, particularly South Korea.
The pictures were released by 38 North, a North Korea monitoring project at Johns Hopkins University, in Maryland.
Bermudez offered two possible explanations - that the test site could be going into "a standby mode" or that the games were meant to confuse observers, given North Korea knows that Punggye-ri is under constant observation.
Satellite images from the next day suggested that the North Koreans had run communication cables into the tunnels.
"Since the North Koreans are aware of when commercial satellites will fly overhead, the presence of personnel at play may be a way of signalling that a decision has been made to place the test on hold".
Satellite images taken of the Punggye-ri nuclear test site in the country's northeast region appear to show people playing volleyball - a popular sport in the country - on three locations of the facility.
The images were taken on Sunday as tensions between the US and North Korea have spiked over nuclear threats, said The New York Times.
The images come at a time where the North Korean nuclear situation is at its most tense - just hours ago state media warned Washington that it was preparing a "super-mighty pre-emptive strike" which would "reduce the USA to ashes".
Senior aides to Trump have said that military options are not off the table in dealing with North Korea's rapidly advancing nuclear and missile technologies.