The U.S. Department of Homeland Security today announced that the People's Republic of China formally joined the Container Security Initiative (CSI). U.S. Customs and Border Protection (CBP) Commissioner Robert C. Bonner and Mu Xinsheng, Commissioner of the General Administration of Customs of the People's Republic of China, today signed a declaration of principles in Beijing, formally initiating joint efforts to target and pre-screen cargo containers shipped from the ports of Shanghai and Shenzhen destined for U.S. ports. "CSI is an essential element of the layered security strategy of the United States," said Homeland Security Secretary Tom Ridge.