China says the United States is the primary source of uncertainty for the international nuclear order and global strategic stability. The statement comes after the U.S. indicated it no longer unilaterally adheres to the zero-yield standard, citing what it described as a Chinese nuclear explosion test in June 2020. On February 28, Chinese Defense Ministry spokesperson Zhang Xiaogang dismissed the allegation as unfounded, stating that China strictly observes a moratorium on nuclear testing and maintains a defensive nuclear policy.