Three US military personnel killed in Osprey crash off Australian coast

Officials confirmed that 23 US personnel were on board the aircraft

US military Osprey aircraft fly in formation off the coast of Sydney in 2017. AFP

Three people have been killed, and several are in a serious condition after a US military aircraft crashed off the coast of northern Australia during exercises on Sunday.

US military officials confirmed US marines were killed after a V22 Osprey helicopter crashed off the coast of Darwin.

“Three have been confirmed deceased while five others were transported to Royal Darwin Hospital in a serious condition,” they said in a statement, adding that 23 US personnel were on board the aircraft.

Recovery efforts are continuing.

The US military said the "marines aboard the aircraft were flying in support of Exercise Predators Run" and that the incident occurred at "approximately 9.30 in the morning."

About 2,500 troops from the US, Australia, Indonesia, the Philippines and East Timor were taking part in the exercise, which is scheduled to end on September 7.

Australian Prime Minister Anthony Albanese said earlier that the crash occurred on Melville Island north of Darwin.

Mr Albanese said Australian personnel were not involved in the crash.

“Our focus as a government and as a department of defence is very much on incident response and on making sure that every support and assistance is given at this difficult time,” he said.

The US and Australia have been stepping up military co-operation in recent years in the face of China's growing presence in the Pacific region.

American troops military was also taking part in a multination military exercise in July when four

Four Australian soldiers were killed when their helicopter crashed into the ocean off the coast of Queensland last month during exercises in which US troops were also taking part.