Russian President Vladimir Putin has ordered military forces in central Russia on combat alert as well as a drill of airborne troops, a day after Ukraine ordered a cease-fire with pro-Russian rebels.
NATO said earlier this week that Russia has resumed a military build-up on the border with Ukraine where pro-Russian separatists have been fighting government forces for weeks in a conflict that has left about 300 people dead and displaced over 34,000.
Ukrainian President Petro Poroshenko ordered his forces to cease fire Friday and halt military operations for a week, the first step in a peace plan he hopes will end the fighting that has killed hundreds.
The Kremlin dismissed the plan, saying it sounded like an ultimatum and lacked any firm offer to open talks with insurgents.
The combat alert in the central military district, which encompasses the Volga region and the Ural mountains but not western Russia, will last until next Saturday, Russian Defence Minister Sergei Shoigu said, quoted by Russian state news agencies.
Some 65,000 troops will take part in military drills accompanying the combat alert, according to head of Russian General Staff General Valery Gerasimov, including several thousand troops of an airborne division which will be moved from a city 200 east of Moscow where they are stationed to the Ural mountains.