US Vice President Mike Pence visited a prominent American hospital without a mask, despite medical center rules that require visitors to wear personal protective equipment.
Mr. Pence appeared to be the only person present without a face mask at the Mayo Clinic in Minnesota.
In a deleted tweet, the clinic said the vice president had been informed in advance of his policy of requiring masks.
Mr. Pence heads the White House Coronavirus task force.
The advice of the United States government on coronavirus prevention is that people should wear face covers “in public places where other social distancing measures are difficult to maintain.”
The Mayo Clinic itself requires that all patients and visitors to its medical centers wear a mask or face covering.
Mr. Pence’s visit occurred the same day that the number of cases of American coronavirus exceeded one million and that the number of deaths exceeded 57,000.
President Donald Trump himself has already declared that he does not intend to wear a mask.
Mr. Pence defended his decision to flout hospital rules if necessary to meet with staff and patients.
“As vice president of the United States, I am regularly tested for coronavirus, and everyone around me is tested for coronavirus,” he said.
“And when the CDC released guidelines on wearing a mask, it was their recognition that people who might have the coronavirus could prevent the possibility of transmitting the virus to someone else by wearing a mask.
“And since I don’t have the coronavirus, I thought it would be a good opportunity for me to be here, to be able to talk to these researchers, these incredible healthcare workers, to look them in the eyes and to say thank you. ”
According to the Axios news site, Mr. Pence has never worn a mask in public since the start of the pandemic while continuing to travel across the country.
An assistant to Mr. Pence was the first member of the White House to test positive for the virus in late March.