WASHINGTON (AP) — This time, he wore a mask. Vice President Mike Pence donned a face covering Thursday as he toured a General Motors/Ventec ventilator production facility in Indiana after coming under fire for failing to wear one earlier this week in violation of Mayo Clinic policy.

Pence on toured the General Motors facility in Kokomo, which had been closed due to the coronavirus and was brought back online in mid-April to produce critical care ventilators for hospitals around the country. The transformed facility has already manufactured hundreds of the units, including some that were sent to hospitals in Gary, Indiana that were struggling with supply.

General Motors requires workers to wear surgical masks at the Kokomo facility except when they are eating lunch, United Auto Workers spokesman Brian Rothenberg said.

Pence's visit to the facily came hours after his wife, Karen Pence, defended her husband's decision to not wear a mask during a Tuesday visit to the Mayo Clinic Rochester, Minnesota, telling Fox News Channel that he had been unaware of the hospital's coronavirus policy until after he left.

Mrs. Pence said the vice president has been following the advice of medical experts and hadn't intended to offend anyone. Pence, like other senior White House staff, is tested for the virus at least once a week.

"As our medical experts have told us, wearing a mask prevents you from spreading the disease. And knowing that he doesn't have COVID-19, he didn't wear one," Mrs. Pence said, adding that it "was actually after he left Mayo Clinic that he found out that they had a policy of asking everyone to wear a mask."

"So, you know, someone who's worked on this whole task force for over two months is not someone who would have done anything to offend anyone or hurt anyone or scare anyone," she said.

The Mayo Clinic had tweeted — then deleted — that it had informed the vice president of its "masking policy prior to his arrival."

"Mayo shared the masking policy with the VP's office," the health care system later said in its response.

The Centers for Disease Control and Prevention recommends that Americans wear cloth face coverings in public settings where other social distancing measures are difficult to maintain, such as in supermarkets, especially in areas of significant community-based transmission.

Footage of Pence's tour of the Mayo Clinic showed him bare-faced as he met with an employee who had recovered from the virus, even though everyone else in the room appeared to be wearing one. He also participated in a roundtable discussion on Mayo's coronavirus testing and research programs during which all of the other participants including Food and Drug Administration chief Stephen Hahn, top Mayo officials, Gov. Tim Walz and U.S. Rep. Jim Hagedorn, donned face coverings.

Pence explained his decision that day by stressing that he has been frequently tested for the virus.

"As vice president of the United States I'm tested for the coronavirus on a regular basis, and everyone who is around me is tested for the coronavirus," Pence said. "And since I don't have the coronavirus, I thought it'd be a good opportunity for me to be here, to be able to speak to these researchers, these incredible health care personnel, and look them in the eye and say 'thank you.'"

But even with a mask, Pence would have been able to look health care workers in the eye because one only covers the nose and mouth.

President Donald Trump has repeatedly expressed discomfort about mask-wearing, saying he did not intend to wear one when the CDC's recommendations were unveiled. And most senior staff have followed his lead, at least when they're in the White House.

People who enter the White House complex have their temperature taken, and those who will be in close proximity to the president and the vice president are given rapid COVID-19 tests to ensure they're not infectious.

Senior staff also are given tests on a rolling basis, so that infections are quickly detected.

For most people, the virus causes mild or moderate symptoms, such as fever and cough that clear up in two to three weeks. But for some, especially older adults and people with existing health problems, it can cause more severe illness, including pneumonia, or death. The virus has now infected more than 1 million people in the United States, and more than 60,000 have died, according to figures compiled by Johns Hopkins University. The number of infections is thought to be far higher because many people have not been tested.