U.S. officials said airlines should consider limiting capacity on planes to promote social distancing, but they are not considering making the airlines do it.

The officials also recommended — but did not move to require — that travelers wear face coverings in airports and on planes. All leading U.S. airlines now require passengers to wear masks, but regulators have refused a request by the airlines to make it a federal rule.

The Transportation, Homeland Security, and Health and Human Services departments made those and other recommendations in a report containing guidelines for reducing the risk of spreading the new coronavirus by air travel.

The agencies said airlines and airports should take steps to increase social distancing, clean surfaces touched by passengers, and ask passengers about their health to discourage people who may be ill from traveling.

The issue of limiting capacity on planes gained new urgency this week when American Airlines joined United Airlines in trying to fill every seat on every flight. The move was criticized by the government’s top expert on infectious diseases, Dr. Anthony Fauci, and Dr. Robert Redfield, director of the Centers for Disease Control and Prevention.