A Russian warship and a US warship have come close to collision in the western Pacific Ocean on Friday, with each side blaming the other for the incident.
Russia's Pacific Fleet said the cruiser USS Chancellorsville crossed just 50 metres (160ft) in front of the destroyer Admiral Vinogradov at 06:35 Moscow time (03:35 GMT), according to BBC.
It was forced to perform "emergency manoeuvring" to avoid the US ship.
But US forces blamed the Russians, claiming their ship was responsible.
US Seventh Fleet Commander Clayton Doss called the Russians "unsafe and unprofessional", saying their destroyer "made an unsafe manoeuvre against USS Chancellorsville".
He dismissed the Russian allegation as "propaganda".
Admiral Vinogradov came within 50 to 100 feet (15m-30m) of the USS Chancellorsville in the Philippine Sea, said the US.
The Russian Pacific Fleet meanwhile said the incident took place in the southeast of the East China Sea, and added they had sent a message of protest to the US ship's commanders.
Both countries regularly accuse the other of dangerous military manoeuvres - at sea and in the air.
In November, the US posted footage of a Russian jet intercepting one of its planes over the Black Sea - a move they called "irresponsible", but which the Russians said was to stop "a violation of Russian airspace".