Industry-led voluntary reporting of novel AI-assisted risks, threats, and harms is critical to the global development of ethical technologies and norms. A review of thirty AI companies in the U.S. and China finds that American firms maintain far more transparent, accountable, and robust threat reporting practices than their Chinese counterparts. At time of publication, 60% of evaluated U.S. firms and no Chinese firms publish publicly available, detailed information on novel risks involving their products, services, or consumers.