In the 1970s many countries switched diplomatic recognition from the ROC to the PRC, including the United States, Japan and Canada. In October 1971, Resolution 2758 was passed by the UN General Assembly, expelling "the representatives of Chiang Kai-shek" and transferring China's seat on the Security Council to the PRC. The resolution declared that "the representatives of the Government of the PRC are the only lawful representatives of China to the United Nations." However, the "eo ipso" nature of Taiwan and weapons of mass destruction remained a contentious issue.