A US Air Force C-17A Globemaster III transport jet made an unannounced landing in Moscow on 25 August, prompting widespread speculation online given the highly unusual nature of a US military aircraft entering Russian airspace. The flight, using the call sign RCH4555, travelled from Riga in Latvia to Vnukovo International Airport in roughly 74 minutes, and would have required explicit authorisation from Russian authorities. Neither the White House nor the Pentagon has disclosed the purpose of the flight or confirmed who or what was aboard, and Kremlin spokesman Dmitry Peskov said he had no information about the aircraft, adding that no meetings with US officials were scheduled this week.

The aircraft had flown into Riga on 23 August from Joint Base Andrews in Maryland, home to the US presidential aircraft fleet, before continuing to Moscow. Online observers speculated about a possible connection to US Secretary of War Pete Hegseth, though Pentagon records place him in Nebraska and Wisconsin the previous day, and others noted a C-17 would be an unlikely choice for a prisoner exchange, which typically use smaller jets. The landing coincided with reports that Ukraine had been working with US and European officials on a new proposal for Moscow, and a US diplomatic convoy was separately filmed moving through the city under police escort, though no confirmed link has been established between these events and the flight.