The plane carrying Prime Minister Anthony Albanese home from his successful trip to Washington has been forced into an unscheduled landing in the US.

After taking off from Andrews Air Force Base, the Royal Australian Air Force Airbus A330-200 taking the prime minister home was meant to fly directly to Hawaii but unexpectedly landed in St Louis, Missouri, after less than an hour in the air.

The move is a precautionary one after a piece of luggage fell from an overhead locker and hit another passenger on the aircraft.

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"It looks like there's been a little mishap inside the plane," 9News national affairs editor Andrew Probyn said.

"We're told it's not very serious, but as a precaution…

"It looks like one of the RAAF staff at the back of the jet has opened an overhead locker and something heavy has fallen on someone below it.

"But I stress it doesn't seem to be too serious, as a precaution they're stopping in Missouri."

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The unscheduled stop has been just about the only blip – aside from Donald Trump clipping Kevin Rudd during an awkward exchange – in what was a tremendously successful trip to Washington for Albanese.

During his White House meeting with Trump, the prime minister inked an $8.5 billion critical minerals deal to combat China's stranglehold on the industry, while the US president was effusive in his praise for Australia and signalled the AUKUS pact will go ahead as planned.

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