SAN FRANCISCO—Mayor Edward Lee will travel to the Vatican later this month to discuss climate change and human trafficking with United Nations leaders and Pope Francis.

Governor Jerry Brown and San Jose Mayor Sam Liccardo will also be in attendance for the two-day event that begins on July 21.

The Pontifical Academies of Sciences and Social Sciences, a scientific academy of the Vatican, will host the conference.

The mayor’s office said Lee will speak at the event and discuss the city’s climate action program and initiatives against human trafficking.

Roger Kim, a senior advisor to Lee on environmental issues, said San Francisco has some of the most advanced environmental policies in the United States. According to Kim, the city reduced greenhouse gas emissions by 23 percent from 1990 to 2012.

The Academy’s website said the main objective of the first day of the event is “for mayors and local administrators to join the religious leaders and the law enforcement authorities in their request to the UN to consider modern slavery and human trafficking as a crime against humanity.”

The workshop on the second day will focus on “how cities can drive the implementation of the new sustainable development agenda and forge a roadmap for their realization.” In addition, mayors and other participants will “consider the challenges of social inclusion, economic development and environmental preservation including cities’ carbon commitments.”

The event comes just two months before leaders from nations across the world meet in New York to approve a set of 17 Sustainable Development Goals.