What is the fine-grained topic of the following text: This meeting follows an announcement by America’s President Obama and China’s President Xi Jinping during the G20 Summit held earlier this month in Hangzhou, China that the U.S. and China will continue to work together to address the illicit supply of fentanyl and its related compounds. Only return the topic.
U.S. and China cooperation on addressing the illicit supply of fentanyl