A US Air Force cargo plane has arrived at an airport on the outskirts of Moscow, flight tracking data shows, sparking speculation about a possible prisoner swap.

The Boeing C-17A Globemaster III, a military transport plane, arrived at Vnukovo International Airport, 17 miles southwest of the centre of the capital, on Tuesday morning.

The plane, with flight number RCH4555, departed the Latvian capital, Riga, just before 7am UK time and landed at Vnukovo slightly more than an hour later, around 10am Moscow time.

The plane departed from Camp Springs in Maryland just outside Washington DC, where Andrews Air Force Base is located, on Sunday evening, landing in Riga early next morning, flight tracking site Flightradar24 showed.

Air Force flight RCH4555 departs Riga, Latvia at 5.50am on 25 August, landing at Vnukovo International Airport, Moscow (Screenshot: Flightradar24)