China to end nuclear tests

China is to join a global moratorium on nuclear testing in September, but will conduct one more blast before then "to ensure the safety of its nuclear weapons", the government said yesterday. The announcement came just hours after an underground explosion at the Lop Nor test site in China's north-west province of Xinjiang.

The latest test attracted international condemnation from critics unmollified by China's pledge to honour the test ban treaty in its own time. The White House said it "deeply regrets" the underground detonation and urged Peking to avoid further testing.

For the past year China has defied world opinion by insisting it would continue testing until a comprehensive test ban treaty came into effect. It has argued that such a treaty should not cover "peaceful" nuclear explosions. But with yesterday's announcement, Peking looks set to fall into line with other world nuclear powers later this year.

Last week in New York, China said it would abandon its plea for an exemption for "peaceful" blasts. This latest statement means that China has also decided to adhere to a moratorium when the test ban treaty is signed, rather than at some future ratification date, as it had previously stated.

"China conducted a nuclear test [on Saturday] and will conduct another one to ensure the safety of its nuclear weapons before September this year. After that, China will exercise a moratorium on nuclear testing," the official Xinhua news agency said. The test ban treaty signing is scheduled for September at the United Nations General Assembly in New York, but negotiators from 38 countries need to meet a 28 June deadline if the treaty is to be ready in time.

According to the Australian Seismological Centre, China's 44th nuclear test had an estimated yield of 20 to 80 kilotons, making it a mid-range explosion.

Peking is likely to come under further criticism for its insistence that it must carry out one final explosion before September.