TOKYO -- The recent assertion by Japan's top diplomat that North Korea is preparing for a new nuclear weapons test has drawn a rebuttal from a U.S.-based monitoring website maintaining that such activity is not confirmed by satellite imagery.
Pyongyang appears to be "working hard to get ready for the next nuclear test," Foreign Minister Taro Kono said at a Saturday lecture in the western Japanese city of Kochi. He cited the removal of soil from a tunnel at the site.
But Johns Hopkins University's 38 North blog, which monitors the reclusive state, said in an analysis dated Monday that "commercial satellite imagery from March 23 shows quite a different picture: namely, that activity at the test site has been significantly reduced compared to previous months."
"Tunneling at the West Portal, a site not associated with any of North Korea's previous tests, had been active earlier this year but has slowed down significantly as has other personnel and vehicular movement around the site," the post continued.
Kono doubled down in a Tuesday news conference, saying that "North Korea is continuing work at nuclear facilities, including the test site, based on a variety of publicly available information."
He suggested that the website supports his claim, citing a reference in the article.
"Nevertheless, it is highly likely that the North Koreans continue to maintain the readiness of the nuclear test facility -- one indication is recent roadwork -- to allow nuclear testing in the future should Pyongyang decide to do so," the article said.
Kono's comments are seen as a call to the international community to keep up the pressure on Pyongyang, which may use summits planned with South Korea for April 27 and expected with the U.S. in late May as a chance to ease it.
With North Korea having taken no visible, definitive steps toward abandoning its nuclear weapons, Kono appears alarmed that nuclear and missile development could be continuing even now.
Even after the possibility of talks emerged in March, Kono has urged countries to tackle sea-based smuggling by North Korea that has continued. He spoke by phone Friday with South Korean counterpart Kang Kyung-wha and U.S. Deputy Secretary of State John Sullivan, now acting secretary of state, to reaffirm cooperation and tighten their response against ship-to-ship transfers meant to skirt sanctions.
The United Nations Security Council decided that day to add numerous shipping companies to its list of sanctions targets. It also designated more vessels as being subject to such measures as asset freezes and blacklisting from ports.