WASHINGTON - The United States will launch a formal diplomatic protest to Russia over a naval encounter in western Pacific, said acting US Defense Secretary Patrick Shanahan on Friday.

"We'll have military-to-military conversations," Shanahan told reporters at the Pentagon.

Russian anti-submarine destroyer Admiral Vinogradov managed to avoid a collision with US guided-missile cruiser Chancellorsville in the East China Sea on Friday, with the latter conducting a dangerous maneuver, the Russian Defense Ministry said.

The incident occurred on Friday at 6:35 am local time (0335 GMT), according to a statement of the Russian Pacific Fleet, published by the ministry's official news agency Krasnaya Zvezda.