President Vladimir Putin says Russia respects the sovereignty of other ex-Soviet republics and that it has made an exception with Ukraine because he says it is under foreign control, the TASS news agency reports.
Ukraine rejects what it says is a stream of propaganda out of Russia, which has built up forces near the border of its former Soviet neighbour and on Monday recognised two chunks of its territory as independent republics.
Putin said Russia was not seeking to re-establish an empire.
"This absolutely does not correspond to reality," Putin said in the Kremlin on Tuesday.
Russia had seen "speculation" on the issue "that Russia wants to re-establish the empire within the imperial borders," Putin said, after he had earlier recognised the Luhansk and Donetsk "people's republics" as independent states.
During a televised address on Monday, Putin had declared that Ukraine owed its existence to the Russian and Soviet empires and also questioned the statehood of Ukraine.
Putin rejected the idea of imperial ambitions again at a meeting with President Ilham Aliyev of Azerbaijan.
The oil-rich South Caucasus country of Azerbaijan on the Caspian Sea was once also part of the empire.
"After the disintegration of the Soviet Union, Russia has recognised all the new geopolitical realities and, as you know, is working to consolidate the cooperation of all countries, independent states that have emerged on the post-Soviet territory," Putin said.
The Soviet Union, founded 100 years ago, disintegrated 30 years ago.
Putin again expressed regret that Ukraine had turned its back on this co-operation with Russia after a bloody coup and a violent takeover.
In his speech on Monday, he had spoken of a "puppet regime" in Kyiv that was not pursuing its own policy but was controlled and used by the US to weaken Russia.
with reporting from DPA