People stand in line while wearing face masks in the Elmhurst neighborhood on April 1, 2020 in New York City.

America's top doctor appears to have softened his stance over the effectiveness of face masks when it comes to preventing the spread of the coronavirus.

U.S. Surgeon General Jerome Adams had initially advised against the general public wearing face masks, saying they were "not effective" in preventing people from contracting COVID-19 and amplified the risk of health-care providers being unable to get them.

"Seriously people — STOP BUYING MASKS!" Adams said via Twitter on Feb. 29.

"They are NOT effective in preventing general public from catching coronavirus, but if healthcare providers can't get them to care for sick patients, it puts them and our communities at risk!" he added.

However, Adams told NBC's "TODAY" show on Wednesday that he has now asked the Centers for Disease Control and Prevention to investigate whether this recommendation should change.

He explained the advice to avoid wearing masks had been based on the "best available evidence at the time" but "we now know there is a significant amount of asymptomatic spread."

Adams also underlined three key points when it comes to wearing face masks, advising people to avoid touching their face, to save the N95 masks for health-care workers who need them and to continue following social distancing guidelines.