A satellite image shows Russian Su-27/30 Flankers and Su-24 Fencers at a military base in Buturlinovka, southern Russia.
An official in the Russian military general staff has said that NATO satellite photographs purporting to show Russian forces concentrated near the Ukrainian border were taken in August 2013, a news report has said.
The report came hours after NATO on Thursday unveiled photographs it said showed Russian deployments of some 40,000 troops, along with tanks, armored vehicles, artillery and aircraft. It said the pictures were taken between March 22 and April 2.
"These photographs that were distributed by NATO depict units of Russian forces of the Southern Military District which conducted various exercises last summer, some of them near the border with Ukraine," the official said, RIA Novosti reported.
President Vladimir Putin secured permission for his parliament last month to send Russian armed forces into Ukraine to protect compatriots there if necessary, prompting Western concerns that Russia could invade the east after annexing the Black Sea peninsula of Crimea from Ukraine last month.
Moscow seized Crimea after Ukraine's pro-Russian president was toppled by protesters seeking closer ties with Europe.
Russia's Southern Military District includes territory bordering southeastern Ukraine. Russia last month announced military exercises in the Southern Military District and areas bordering Ukraine further north, and has dismissed U.S. and European concerns about the troop numbers.