Chief executives of the nation’s largest passenger and cargo airlines met with key Biden administration officials Friday to talk about reducing emissions from airplanes and push incentives for lower-carbon aviation fuels.

The White House said the meeting with climate adviser Gina McCarthy and Transportation Secretary Pete Buttigieg also touched on economic policy and curbing the spread of COVID-19 — travel has been a vector for the virus. But industry officials said emissions dominated the discussion.

United Airlines said CEO Scott Kirby asked administration officials to support incentives for sustainable aviation fuel and technology to remove carbon from the atmosphere. In December, United said it invested an undisclosed amount in a carbon-capture company partly owned by Occidental Petroleum.

A United Nations aviation group has concluded that biofuels will remain a tiny source of aviation fuel for several years. Some environmentalists would prefer the Biden administration to impose tougher emissions standards on aircraft rather than create breaks for biofuels.