Washington: For the first time in a move to test homeland defences of US, an exercise brings four combatant commands together this week to simulate how the military would respond to an attack on its home turf.

Headed by US Northern Command, the four-day exercise began off the east coast and also involves US Space, Transportation and Strategic commands, according to NORTHCOM.

The aircraft carrier Harry S Truman strike group and its air wing will join Canadian fighter jets and Air Force F-15s in conducting intercepts against adversary aircraft during the exercise, which began on May 28 and will wrap up on May 31.

The Harry S Truman Strike Group concluded its deployment, but will be kept at sea amid COVID-19 concerns, the service announced.

The current deployment is the aircraft carrier’s third overseas cruise in the last four years.

While the strike group’s deployment began to wrap up this spring, it spent its time as a rapid-response force at sea instead of pierside in order to protect the crew from exposure to COVID-19.

An Air Force B-1B bomber will be used as the enemy aiming to infiltrate US airspace as well.

Along the way, it is hoped the exercise can strengthen the military’s ability to communicate and share real-time information in such a scenario, according to NORTHCOM.

US Transportation Command is providing refueling tankers along the coast to support defending forces during the exercise, and Space Command is providing satellite communications and GPS.

“Leading complex multi-combatant command operations across multiple domains demonstrates our readiness to defend our homeland regardless of COVID-19,” Air Force Gen Terrence O’Shaughnessy, the head of NORTHCOM, said in a statement.