United Airlines is expanding its mask requirements as a surge in COVID-19 cases stalls a rebound in air travel. The Chicago-based carrier says travelers over the age of two must wear face coverings in gate and baggage claim areas, airline lounges and customer service counters and kiosks. That’s in addition to passengers being required to wear masks on planes. Those who refuse can be banned from flying United while masks are required, and possibly longer. The move comes as U.S. air travel had started to bounce back until recent spikes led to new quarantine requirements for travelers from hard-hit areas.