China on Tuesday pushed back at renewed suggestions that the COVID-19 pandemic could have been the result of a lab leak, saying it has been “open and transparent” in the search for the virus’ origins.

Recently, the U.S. Department of Energy assessed with “low confidence” that the pandemic that was first detected in the central Chinese city of Wuhan in late 2019 began with the leak of a virus from a lab. The report hasn’t been made public and officials in Washington stressed that U.S. agencies are not in agreement on the origin.