Russia's SVR foreign intelligence service on Monday dismissed growing Western allegations that Moscow is planning an invasion of Ukraine.
Western countries have this month raised alarm over reported Russian military activity near Ukraine, with the US saying it has "real concerns" over what it called "unusual activity".
"The Americans are painting a frightening picture of hordes of Russian tanks that will start to crush Ukrainian cities, saying they have some 'reliable information' of such Russian intentions," the SVR said in a rare statement to Russian news agencies.
It said the US is sending its allies "absolutely false information on the concentration of forces on the territory of our country for the military invasion of Ukraine".
The SVR said, "US bureaucrats are scaring the global community".
The Kremlin earlier Monday said the West is leading an "information campaign" on the issue with the aim of "escalating tensions".
"Any movement of Russian troops inside our territory does not pose a threat to anyone and should not cause concern to anyone," Kremlin spokesman Dmitry Peskov told reporters.
He previously dismissed the Western claims as "hysteria".
In its statement, the SVR also said it had information on "creeping advances" by the Ukrainian armed forces, as well as Ukraine organising a "concentration of forces" in areas bordering Russia and Belarus.
Kiev has said it would deploy thousands of border guards and security personnel to its frontier with Belarus because of a migrant crisis that has seen tensions soar between the EU and Minsk.
Ukraine's Foreign Minister Dmytro Kuleba said on Twitter that Russian accusations of Kiev "plotting a military attack" in its separatist east are "false".
He said Ukraine is "working hard to revive" peace talks with France and Germany as mediators and called on Moscow to "engage constructively in these peace efforts instead of undermining them".
France and Germany had accused Moscow last week of breaking diplomatic rules by publishing confidential correspondence over the planning of peace talks.
Russian President Vladimir Putin last week said the West was "escalating" the Ukraine conflict by holding drills in the Black Sea. He also said the US flew bombers near Russia's borders.
Ukraine's army has been locked in a simmering conflict with pro-Russian separatists in two breakaway regions bordering Russia since 2014, after Moscow annexed Crimea.
Kiev and its Western allies accuse Russia of sending troops and arms across the border to support the separatists — claims Moscow denies.
