A foreign ministry spokesman in Moscow said he needed to receive 100 per cent proof of North Korea's role in the sinking of the corvette in March.
Russian specialists are studying the materials of the investigation and will draw their own conclusions.
Chinese specialists are also examining the results of the investigation.
But South Korea has refused to hand details of the inquiry over to North Korea, which had asked for access to the data.
The investigation, which included experts from South Korea, the United States, Australia, Britain and Sweden, declared there is “overwhelming evidence” of North Korean responsibility.
They say the South Korean vessel was sunk by a North Korean torpedo, which North Korea denies.
The United States, meanwhile, has expressed vocal support for its ally South Korea and has been encouraging South Korean military manoeuvres in the area.
Meanwhile on Thursday, the United States has said it will offer North Korea and Iran a "clear choice" in its new national security strategy, accept US offers of engagement, or face “deep isolation” over their nuclear programs.
Some 10,000 people rallied in Seoul Thursday calling for revenge attacks against North Korea, shouting "Let's kill mad dog Kim Jong-Il!"
The North has put its military on alert and scrapped a pact with South Korea. The government said the military would attack immediately if the South's navy crosses the Yellow Sea border, and threatened to shut down a joint business project.