Alaska Airlines has applied to the federal government for two new flights at Ronald Reagan Washington National Airport, including one that would enable direct service between San Diego and Washington, D.C.

A statement from the Seattle-based airline said San Diego and Portland, Ore., are the two cities with the largest passenger demand that don’t already have direct flights to National. If its request is approved by the Department of Transportation, Alaska Airlines would offer one daily round-trip flight to each city.

National is one of the few domestic commercial airports in the nation that require an act of Congress to add flights. To be considered for four roundtrip flights longer than 1,250 miles that Congress authorized last month, airlines were required to submit applications to the Transportation Department by March 12.

Alaska applied for two of the four flights, the statement said. The DOT is expected to make a decision in May, and if Alaska is awarded the slots for San Diego and Portland, the carrier could begin service as soon as late August.

No other carrier currently provides nonstop service to Reagan National from Portland or San Diego. Alaska Airlines currently operates three daily nonstop flights to Reagan National: two from Seattle and one from Los Angeles.

Alaska Airlines is a subsidiary of Alaska Air Group Inc.

— Lou Hirsh