Targeting the Russian oil and gas sector with sanctions is a tacit act of economic warfare, Russian Prime Minister Dmitry Medvedev said Friday.

"We are in a fundamentally different situation at present: equipment for hydrocarbons production has essentially become a token of political struggle and political bargaining," the prime minister said.

Members of the European Union are considering tightening the sanctions noose on Russia as conflict in eastern Ukraine continues. Political upheaval began in former Soviet republic Ukraine in late 2013 as the government in Kiev moved closer to the EU. Sanctions met a Russian move last year to annex the Crimean Peninsula of Ukraine.

Medvedev said energy, a prime source of government revenue, was the main target of sanctions.

The International Monetary Fund in January warned the low price of oil is "clearly bad news" for economies like Russia's that depend heavily on export revenue. The adverse effect for Russia, the fund warned, is likely to be "very large."

A forecast for 2015 from the Russian Economy Ministry said export revenues would decline as Russian energy products wane from the world market.

The Russian Central Bank said Friday the currency has stabilized, trading at around 49 rubles per U.S. dollar. The ruble had reached a 62-1 exchange earlier this year.

"So far I see no need for additional measures," Central Bank President Elvira Nabiullina said.