The Pentagon has accused Russia of violating Ukraine's sovereignty by sending an aid convoy into the country, and warned that it must withdraw all vehicles and personnel "immediately".
Rear Admiral John Kirby, the Pentagon's press secretary, said in a press conference:
Russia should not send vehicles, persons or cargo of any kind into Ukraine, whether under the guise of humanitarian convoys or any other pretext, without Kiev's express permission.
This is a violation of Ukraine's sovereignty and territorial integrity by Russia.
Russia must remove its vehicles and its personnel from the territory of Ukraine immediately. Failure to do so will result in additional cost and isolation.
More top news
Britain's Got Talent star Ryan Howell has died of bone cancer, aged just 18.
A computer game which required players to stack as many slaves as they can into a ship's hold has been withdrawn after a furious backlash.