United States authorities have confirmed they do not expect to find three marines alive, with a rescue operation shifting to a "recovery effort" after a military aircraft crashed about 30 kilometres off the Queensland coast on Saturday.

Key points: Twenty-three out of 26 crew members were rescued after the "mishap" off the Queensland coast

Twenty-three out of 26 crew members were rescued after the "mishap" off the Queensland coast The personnel were here to participate in joint exercises with Australian forces

The personnel were here to participate in joint exercises with Australian forces President Donald Trump has been briefed on the search

Twenty-six crew members were aboard the MV-22 Osprey when it was involved in a "mishap" about 4:00pm (AEST) on Saturday, US authorities said.

The search for the crew members continued throughout the night but was called off on Sunday morning.

"Operations have now shifted to recovery efforts," a statement from the III Marine Expeditionary Force (III MEF).

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"The next of kin for the three missing marines have been notified."

The III MEF said recovery efforts would continue "as the sea state permits" with assistance from the Australian Defence Force, which will send a survey ship and Navy divers.

Defence Minister Marise Payne said a number of assets would support the US-led operation, including the HMAS Melville and a Navy clearance diving team.

"Recovery and salvage operations can take several months to complete," the III MEF statement read.

"The circumstances of the mishap are currently under investigation, and there is no additional information available at this time."

Sorry, this video has expired The craft was in Queensland for Talisman Sabre

Earlier, III MEF said the Osprey aircraft had launched from the USS Bonhomme Richard and was conducting "regularly scheduled operations" when it "entered the water".

Twenty-three people were rescued within an hour, including one marine who was taken to Rockhampton Base Hospital.

The injured marine is expected to be transferred to Brisbane today.

"Please keep the families of those involved in the Osprey mishap near Australia in your thoughts and prayers," Commandant of the US Marine Corps Robert Neller tweeted.

One marine was taken to the Rockhampton Hospital. ( ABC News: Isabella Higgins )

Ms Payne confirmed last night that no Australian personnel were involved in the mishap.

"I have briefed Prime Minister [Malcolm] Turnbull and spoken with Secretary [James] Mattis this evening to offer Australia's support in anyway that can be of assistance," she said in a statement.

"Our thoughts are with the crew and families affected."

Queensland Premier Annastacia Palaszczuk said the state's prayers were "with those US military personnel involved in the incident".

The aircraft had been in Queensland as part of the Talisman Sabre joint training exercise between Australian and United States military forces, which ended on July 25.

A post on the USS Bonhomme Richard's Facebook page on Saturday said the landing helicopter dock had begun "amphibious integration training … exercises out here on the Coral Sea".

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The unusual aircraft involved in Saturday's training mishap off Shoalwater Bay has been described as "an exceptionally difficult aircraft to fly".

Executive Director of the Australia Defence Association, Neil James, said the Osprey was unlike any other aircraft.

"It's to do with the operating envelope. It's a rotary wing aircraft and a fixed wing aircraft and that makes it pretty unique particularly when it's landing or taking off," said Mr James.

Despite the difficulty, the Osprey had a good safety record, he said.

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"It's had 10 crashes over a nearly 20-year period with lots of hours flown including 18,000-odd hours in combat so the ratio of crashes to the airframe over its operating life isn't unusually high, particularly for something that is so difficult to fly," Mr James said.

"Most of the crashes have been attributed to the difficulty in flying it."

He said the recovery and salvage would predominantly aim to retrieve the bodies of the missing Marines.

"If the missing air crew are dead, they're probably still in the aircraft," Mr James said.

The Osprey is a tilt-rotor aircraft that takes off and lands like a helicopter, but flies like an aeroplane.

They have been involved in a series of high-profile crashes in recent years.

In December, five crewmembers of an Osprey had to be rescued after their craft conducted a shallow-water landing off Okinawa after a training mishap in which a rotor blade cut a refuelling hose, according to the Marine Expeditionary Force.

In January, three US soldiers were injured in the "hard landing" of an Osprey in Yemen.

ABC/wires