The Russian military has information about a planned ballistic missile launch by North Korea, a senior military source was quoted as saying by Interfax news agency on Wednesday.
"We have certain information on the type and characteristics of the rocket. However there is no precise information on the timing of its launch," the source in Russia's General Staff told Interfax.
He added that Russia would be monitoring the launch. It was unclear whether he was referring to a short- or long-range missile.
Separately, the ITAR-TASS news agency quoted a source in the Russian foreign ministry as saying: "Judging by everything, a launch will take place. There are signs that preparations for this are underway."
North Korea has launched a series of short-range missiles since carrying out a nuclear test on May 25.
South Korean officials and US have said there are signs that the reclusive Communist state may also be preparing to test-fire a long-range missile.
Tensions have been running high since Pyongyang launched a long-range rocket in April, tested a nuclear bomb in May, then launched a series of short-range missiles and renounced the truce that ended the Korean War in 1953.
Russia has a short border with North Korea and is part of the six-party negotiations aimed at convincing the country's isolated Communist regime to give up its nuclear programme.