These are then smuggled into the United States, the officials say. Last month, the United States imposed sanctions on 28 people and entities involved with the international proliferation of illicit drugs, including a large China-based network. Biden is also due to meet with Mexican President Andres Manuel Lopez Obrador in San Francisco. In San Francisco, state and local officials have tried to clean up drugs from the city's streets, with limited success. "We know San Francisco - and cities across the United States - will benefit from more targeting of the trafficking and production of fentanyl worldwide," a spokesperson for Breed said in a statement.

---

Persons: Joe Biden, Xi Jinping, Biden, Xi, Mike Odeh, Jake Sullivan, Washington, General Merrick Garland, Andres Manuel Lopez Obrador, Alicia Barcena, Brooke Jenkins, Mayor London Breed, Breed, Michael Martina, Sayantani Ghosh, Michelle Nichols, Josie Kao Organizations: Customs, Port, U.S . Customs, FRANCISCO, U.S, Economic Cooperation, United, city's, APEC, U.S . Centers for Disease Control, Prevention, . National, Washington, Biden, Institute of Forensic Science, China's Ministry of Public Security, Commerce, San Francisco . Mexican Foreign, Mayor London, Thomson Locations: Arizona, Mexico, Nogales , Arizona, U.S, Asia, Pacific, San Francisco, United States, China, CHINA, MEXICO, Washington, San Francisco . Mexican, Francisco's