Navy officials say that due to the time elapsed since the crash, survivability is extremely unlikely.
The location of the crash site is known, and an extensive area has been searched multiple times by various ships and aircraft.
Three crew members were found Sunday alive and in stable condition.
The MH-60S Knighthawk was operating with the guided-missile destroyer USS William P. Lawrence when it went down in the central Red Sea, which lies between Africa and the Arabian Peninsula.
The cause of the crash is under investigation; however, the Navy said it "was not due to any sort of hostile activity."