New York City Mayor Bill de Blasio doubled down on his commitment to reopen schools for in-person learning next month, a day after the city's teachers union said his reopening protocol was insufficient to prevent the spread of Covid-19, Reuters reports.

The mayor and schools chancellor Richard Carranza released a “Back to School pledge” outlining the features of their reopening plan, including that all schools will have a 30-day supply of personal protective equipment at all times and schools will close if the percentage of positive Covid-19 tests in the city is three per cent or more on a seven-day average.

“We are going to make sure these schools are safe and ready. And if we don't think they're safe and ready, they won't reopen,” de Blasio said.