Trump will speak to student supporters in Phoenix, where the city council and mayor have made face masks mandatory for people inside a building less than six feet away from others.
Phoenix Mayor Kate Gallego told CNN that she hopes everyone attending the event will wear a mask -- including the President, who has previously claimed that masks don't do much in battling the virus, in direct contradiction to health experts.
“It is not safe right now to have any large events, whether it be the President of the United States or large indoor sporting event,” Gallego said.
Alarming spike: Arizona's cases have nearly doubled in 14 days.
On June 7, the state reported 26,989 total cases, according to Johns Hopkins University.
On Sunday, that figure reached 52,390.
There have been 1,339 coronavirus-related deaths in the state since the start of the pandemic, according to Arizona's health website.