India has signed $1 billion deal with which country for 4 P-8I submarine hunter aircrafts?

United States
India has recently signed $1 billion deal with US aerospace major Boeing for purchasing 4 additional P-8I (Poseidon Eight India ) long-range maritime patrol aircraft. With this, the naval surveillance capabilities of Indian Navy will increase. The P-8I is a long-range anti-submarine warfare, anti-surface warfare, intelligence, surveillance and reconnaissance aircraft capable of broad area, maritime and littoral operations.