Delta Air Lines Inc. is planning an additional $175 million project at John F. Kennedy International Airport’s Terminal 4 — part of a larger expansion effort in the New York region.

Under the expanded program, Terminal 4’s Concourse B will house 27 Delta gates and replace Delta’s current Terminal 2 regional-jet operation. All gates will be designed to accommodate two-class regional jets as well as provide flexibility for gating additional mainline aircraft.