United expands mask mandates to airports

At United Airlines, it will not be enough for passengers to wear a mask just on board its flights. Starting Friday, they'll have to wear face coverings at airports worldwide where United operates. That means masks will be required at all United customer service counters, kiosks, gates, baggage claims and United clubs.

If passengers refuse, they may be denied travel or banned from flying United while the rule is in effect.

The airline is also tightening its mask exemption policy. Before, passengers with certain medical conditions were exempt. But now, they'll have to contact the airline or talk to a representative at the airport. Kids under the age of two are exempt.

Rival Delta Air Lines also strengthened its mask policy this week, saying doctors must clear exemptions.

Airlines say their hospital-grade air filtration systems make flying safe. But Delta and United acknowledge they don't expect demand to return to pre-pandemic levels until a vaccine or treatment is found.