Russia is taking precautionary security measures, including military ones, because it fears tensions over North Korea's atomic test could descend into nuclear war, news agencies quoted an official as saying on Wednesday.
Interfax quoted an unnamed security source as saying that a stand-off triggered by Pyongyang's nuclear test on Monday could affect the security of Russia's far eastern regions, which border North Korea.
"The need has emerged for an appropriate package of precautionary measures," the source said.
"We are not talking about stepping up military efforts but rather about measures in case a military conflict, perhaps with the use of nuclear weapons, flares up on the Korean Peninsula," he added.
North Korea has responded to international condemnation of its nuclear test and a threat of new UN sanctions by saying it is no longer bound by an armistice signed with South Korea at the end of the 1950-53 Korean War.
Itar-Tass news agency quoted a Russian foreign ministry official as saying the "war of nerves" over North Korea should not be allowed to grow into a military conflict, a clear reference to Pyongyang's decision to drop out of the armistice deal.
"We assume that a dangerous brinkmanship, a war of nerves, is under way, but it will not grow into a hot war," the official told Tass. "Restraint is needed."
The foreign ministry often uses statements sourced to unnamed officials, leaked through official news agencies, to lay down its position on sensitive issues.
Russian President Dmitry Medvedev has condemned North Korean tests but his Foreign Ministry has warned the international community against hasty decisions.
Russia is a veto-wielding permanent member of the U.N. Security Council, which is preparing to discuss the latest stand-off over the peninsula.
In the past, Moscow has been reluctant to support Western calls for sanctions. But Russian officials in the United Nations have said that this time the authority of the top international body is at stake.
"We cannot provide cover for any actions that lead to the destabilisation of the non-proliferation regime," Interfax quoted its foreign ministry source as saying.
The Interfax source made clear Russia has not finally made up its mind on the UN vote yet. "We should not subscribe to any specific option beforehand," the source said.
However, the Tass source indicated Russia could back sanctions.
"The (UN Security Council) resolution is most likely to involve sanction-like measures," he said. "The UN Security Council is engaged in a tough work."