Delta Air Lines (DAL -0.55%) said late Thursday that it would require employees and passengers to wear masks through the end of the year, the latest effort by an airline to reassure passengers as the industry tries to spark a rebound in travel demand.

Airlines have been hard hit by the coronavirus pandemic, with Delta last week reporting second-quarter revenue down 88.2% year over year. With flight schedules cut and the carriers in desperate need of revenue, some in the industry have resumed booking to capacity. But Delta reiterated its intention to prioritize safety until the pandemic is resolved.

A Delta airplane parked on the tarmac.

Image source: Delta Air Lines.

In an email to customers on Thursday, CEO Ed Bastian said that the airline will test "virtually" all employees in the next four weeks, looking to identify infected individuals and give them time to recover. The airline is also requiring masks through Dec. 31, and reiterated its commitment to blocking middle seats through the end of September at least, and continuing to limit capacity for the foreseeable future.

"Amid all that is going on across the world, you can continue to expect an unmatched level of care from Delta," Bastian wrote. "When you travel, you can be confident in our steadfast commitment to getting you where you need to go safely."

The entire industry has adopted new safety standards to fight COVID-19, but Delta seems to be trying to market itself as a leader in safety even at the expense of added revenue. Rivals American Airlines Group and United Airlines Holdings have come under fire from lawmakers this month for lifting capacity restrictions .