Russian President Vladimir Putin has strongly denied claims that Russia is using its energy resources as a lever to put pressure on other countries.
Mr Putin says Russia's energy policy is shaped by the market
He was addressing the world's media at his annual news conference in Moscow.
Mr Putin said Russia's energy deals with Ukraine and other neighbouring countries "benefit the consumers" and "experts understand this".
On the poisoning of ex-spy Alexander Litvinenko in London, Mr Putin said he did not believe in conspiracy theories.
"As for what happened there, this, I repeat, can only be answered by the investigation."
There has been some speculation in the Russian media that enemies of Mr Putin may have had a hand in Mr Litvinenko's death, to put the Kremlin in a bad light. Mr Litvinenko was a vehement critic of Mr Putin.
Mr Putin said Mr Litvinenko "did not possess any secrets" that could have damaged Russia.
In a wide-ranging, marathon news conference, Mr Putin said Russia was now one of the world's most powerful economies, with a rapid growth rate - about 6.9% in 2006 - and declining inflation.
Mr Putin insisted that Russia's price increases for energy exports were driven by necessary market adjustments.
He said Russia could not continue Soviet-style energy subsidies for its former Soviet bloc neighbours.
"We're not obliged to subsidise the economies of other countries," he said. "Nobody does that, so why are they demanding it of us?"
In January a Russian row with Belarus over oil exports revived concern among Russia's energy customers in the EU.
"We are always told that Russia is using its ... economic resources to achieve foreign policy aims. That is not the case," Mr Putin insisted on Thursday.
No named successor
Mr Putin is due to leave office in March next year and so far it is not clear who will take his place.
He declined to state any preference for a successor, saying voters would have a "free, democratic" choice.
"There will be no successor. There will be candidates to the presidential post," he told the news conference.
"The authorities' goal is to ensure the elections are held democratically.
"I, too, am a citizen of the Russian Federation, which I am very proud of, and of course have the right to express my preferences but I will only do it during the election campaign."
Under the constitution Mr Putin has to stand down in 2008, after serving two terms. But he has now become so powerful and popular that it is widely assumed whoever he names as the preferred candidate will win the election, the BBC's Richard Galpin reports from Moscow.
"For the time being I'm not going anywhere... Are you trying to shove me out before my time is up? I'll go by myself," Mr Putin said.
More than 1,000 members of the Russian and foreign media registered for the news conference, which has become an annual event.