NEW YORK—New York City Mayor Bill de Blasio said Monday he does not plan to reinstate a citywide mask mandate even as COVID-19 cases increase, opting instead to focus on vaccinating more residents. There have been calls for New York City to follow the lead of Los Angeles County, which announced last week that it will require masks to be worn indoors amid a sharp increase in virus cases. But De Blasio insisted vaccinations are a better strategy for the nation’s most populous city. “Masks have value, unquestionably, but masks are not going at the root of the problem. Vaccination is,” the mayor said during a livestreamed press briefing. “So we do not intend a mask mandate. We do intend to double down on vaccination.”