SINGAPORE — As the only country to have been attacked with atomic bombs, Japan has been a leader in the campaign for nuclear disarmament since the end of the Second World War.

However, when Japan's Foreign Minister Katsuya Okada called on China the other day to join the United States and Russia in cutting its nuclear arsenal and suggested that Beijing was failing to keep its promise to disarm, his comments drew a sharp rebuke.

A spokesman in Beijing said May 17 that China's Foreign Minister Yang Jiechi, at a meeting with Okada in South Korea, had immediately rebutted such "irresponsible" remarks, pointing out that China was the only nuclear-weapons state that undertakes not to be the first to use nuclear arms and not to use or threaten to use them against nonnuclear- weapons states or zones established by treaty to be free of nuclear weapons.