The recent slump in oil prices is expected to result in yearly revenue cuts of $180bn, according to a senior official at the Russian finance ministry.
"Oil price has fallen from 100 dollars to about 50 dollars per barrel. This would result in a decrease in Russian export revenues of 180 billion dollars a year," Maxim Oreshkin, head of the ministry's strategic planning department, told a meeting in the Federation Council, the upper house of the Russian parliament.
The country is set to lose about 2.1tn roubles (£22bn, €30bn, $34bn), or 14% of planned revenues, only from the taxes.
Earlier, the Russian central bank estimated revenue losses at $160bn per year, if oil prices remain around $45 per barrel.
Oreshkin noted the only way Russia has to balance its accounts could be by cutting its imports.
"The main task of the government is to alleviate the shock and to help the economy reach a new balance as soon as possible," he was quoted as saying by Interfax news agency.
He also pointed out the "spiraling inflation", which recently rose to about 16% in annual terms, as the principal challenge to the economy, and called on the central bank to control the pace of inflation.
Russia, one of the largest oil producing nations, has been hit by the fall in oil prices, declining by about 50% since June 2014. In addition, the country faces Western sanctions in connection with the political row over Ukraine.
Credit rating agency Moody's Investor Service earlier downgraded Russia's sovereign debt to junk status. Russian Finance Minister Anton Siluanov charged that the move was driven by political factors. Moody's cited the conflict in Ukraine, low oil prices and the weakened rouble as reasons for the cut.
Standard & Poor's cut the country's credit rating to junk in January, while Fitch Ratings cut its rating to just above junk level.