Japan has confirmed vehicle activity at a North Korean nuclear testing site, but it was unclear whether tests were imminent, a news report said Thursday.
Vehicles have been seen entering and leaving a nuclear testing site in the northeast of the country, Kyodo News agency reported, quoting an unnamed government official.
It was unclear whether any nuclear tests by the North were imminent, but Japan will continue to closely monitor the situation, the official was quoted as saying.
A Foreign Ministry official who spoke on condition of anonymity, citing protocol, said Japan was continuously analyzing intelligence but said the government would not discuss specifics because of the sensitivity of the matter.
A news report last week that U.S. officials were monitoring potentially suspicious activity at a suspected underground nuclear site sent diplomats in the region scrambling to avert a possible test and get Pyongyang to return to multinational talks on its nuclear ambitions.