President Donald Trump threatened on Wednesday to cut funding in schools if they do not open this fall, despite the ongoing coronavirus pandemic.

After the White House forum, where Trump promised to pressure local governors to open schools in fall, Trump posted his threats on Twitter, promising to defund schools if they do not restart in-person classes in the fall semester.

New York City Mayor Bill de Blasio responded to Trump’s threats with the news that schools would not fully reopen in September. In-person classes will be held only one to three days a week to avoid crowds and to comply to social distancing rules. The chief public health officer in Los Angeles County told school officials on Tuesday that they should be ready to continue remote education, with California being one of the states with a surge of recent coronavirus cases. Many universities have recently announced they are switching their fall semester to be entirely online.

Trump cannot unilaterally cut federal funding for schools but he can stop federal grants and bailouts, as part financial relief package.

Sasha Pudelski, an assistant director of policy and advocacy for AASA, the School Superintendents Association, tweeted that Trump would not be able to do it without Congress.

Other education professionals similarly criticized Trump’s remark.

“Nothing that Donald Trump has said in the last 48 hours has been safe or responsible,” Lily Eskelsen Garcia, president of the National Education Association, told CNN.

Trump’s urge to re-open schools comes amid a dramatic surge in coronavirus cases in 31 states, with the nationwide daily cases increasing to more than 56,000. More than 130,000 people have died of coronavirus complications.