Presumptive Democratic nominee Joe Biden and Sen. Kamala Harris (D-CA), his number two on the party’s ticket, used their first joint policy address to call for a national mask mandate to protect against the spread of COVID-19. The brief speech was their second appearance together since Biden announced Harris as his running mate on Tuesday. The duo made news quickly.

“Every single American should be wearing a mask when they’re outside for the next three months,” the former vice president said. “At a minimum.” He urged governors across the country to use their powers to follow his direction. Biden added that estimates from health specialists approximate that the measure would “save over 40,000 lives in the next three months.” 

“We just witnessed real leadership,” Harris said.

The speech followed guidance Biden and Harris received from members of the public health and economic communities earlier on Thursday. Neither Democrat took questions. The two leaders are expected to appear together again in the coming days. The Delaware News Journal reported that they will both give convention remarks at the Chase Center in Biden’s home city of Wilmington, where he and Harris both spoke on Wednesday.