“New Yorkers deserve to have the assurance that somebody that is next to them, in a confined area, has vaccinated themselves or has tested negative,” Mr. Espaillat said.
Los Angeles County reinstated its mask mandate last month, and Washington began to require masks over the weekend. The Democratic mayors of Atlanta and Kansas City, Mo., have reinstated forms of mask mandates, and Chicago’s mayor is considering one.
In Louisiana, Gov. John Bel Edwards, a Democrat, said statewide indoor mask requirements would apply to all people ages 5 and older, adding that the rise in virus cases and hospitalizations were “threatening the ability of hospitals to deliver care.”
Dr. Naveena Bobba, San Francisco’s acting health officer, characterized the city’s move as a temporary but necessary measure to “help us deal with the Delta variant, which is causing a sharp increase in cases, and we know increases in hospitalizations and deaths will follow.”
Many Republican governors have resisted the idea of mask mandates. Last week, Gov. Greg Abbott of Texas issued an executive order barring local governments and state agencies from mandating vaccination and reinforcing an earlier order that prohibited officials from requiring face masks.
Gov. Ron DeSantis of Florida last week signed an executive order giving parents the power to decide whether their children should wear masks in schools, after Broward County, the state’s second largest school district, voted to require masks.
“In Florida, there will be no lockdowns,” Mr. DeSantis said to cheers at a restaurant in Cape Coral, Fla., on Friday. “There will be no school closures. There will be no restrictions and no mandates.”