China, the only country not observing a moratorium on nuclear tests, conducted an underground nuclear explosion on Monday in its western desert.
The test came just four days after 178 nations agreed to indefinitely extend the Nuclear Non-Proliferation Treaty, intended to stop the spread of atomic weapons. China has continued testing in defiance of the moratorium and calls by the United States, Japan and other nations to stop.
A Foreign Ministry spokesman said China will stop nuclear testing once a comprehensive test ban treaty is implemented by next year, as provided for by the Non-Proliferation Treaty.
The official Xinhua news agency did not say where the test took place, but the Australian Seismological Center said it was at Lop Nor, in the Xinjiang region of far western China. It estimated the blast was equivalent to 40 to 150 kilotons of dynamite.
Leif Nordgren, a seismologist at the Swedish defense research agency FOA, described Monday’s blast as “rather small.”