Asian neighbors have reacted nervously to China's nuclear test, expressing fears that it might jeopardize efforts to enforce the international nuclear controls treaty in the region.
South Korea, currently bogged down in nuclear talks with its rival North Korea, said Wednesday that the test was regrettable.
"Our government regrets that the Chinese nuclear blast came at a time when major nuclear countries refrain from nuclear testing and efforts grow to conclude a conclusive nuclear test ban treaty," South Korea's Foreign Ministry said.
North Korea's rejection of international inspections has made the issue of nuclear controls particularly urgent for the region.
Japan's Foreign Ministry similarly expressed regret after Tuesday's underground blast in China's northwestern Xinjiang region.
The United States has been leading international efforts to conclude a multinational agreement on a conclusive test ban treaty, tentatively by 1996.