The carrier will do so on all flights departing through to April 30th.
Delta said the moves were designed to ensure customers can confidently plan and book their spring travel.
The airline has consistently listened to its customers and prioritized their preferences by offering more space through seat blocking and reducing the overall number of people on board each flight since April last year.
“We want our customers to have complete confidence when traveling with Delta, and they continue to tell us that more space provides more peace of mind,” said Bill Lentsch, chief customer experience officer for Delta.
“We’ll continue to reassess seat blocking in relation to case transmission and vaccination rates, while bringing back products and services in ways that instil trust in the health and safety of everyone on board – that will always be Delta’s priority.”