By Alexei Anishchuk and Timothy Heritage
MOSCOW (Reuters) - President Vladimir Putin backed a ban on Americans adopting Russian children on Thursday in a feud over a U.S. law that aims to punish Russians accused of violating human rights.
In his first annual news conference since he began a new six-year term in May, the former KGB spy often struck a hawkish tone, signaling support for tough retaliation against the "unfriendly" Magnitsky Act passed by Moscow's former Cold War enemy, which he said was poisoning relations.
He also held up a court ruling that will free former oil tycoon Mikhail Khodorkovsky - a fierce critic of Putin's rule - from jail two years early in 2014 as evidence that he does not control the courts.
The 4-1/2-hour performance, broadcast live, was intended to end speculation about the 60-year-old's health and portray him as the guarantor of stability in a country that was under Soviet communist rule two decades ago.
"This is by no means the least successful period in Russia's history," he said, adding: "Because I love Russia."
"Without irony, I look forward to any future president being more successful."
Sitting in an immaculate suit and tie behind a large desk in front of 1,200 journalists in a Moscow conference center, Putin calmly took questions, some of them hostile, on issues from pensions to the crisis in Syria.
Occasionally sipping tea as journalists frantically waved their arms in the hope of asking a question, he became most animated when asked about the legislation signed by President Barack Obama last week.
The Magnitsky Act, drawn up over concern about the death in a Russian prison of anti-corruption lawyer Sergei Magnitsky in 2009, will deny visas to Russians accused of human rights abuses and freeze their assets in the United States.
"This, of course, poisons our relationship," he said of the measures.
Russia's lower house of parliament has prepared a tit-for-tat law to prevent Americans adopting Russian children and bar entry to U.S. citizens accused of abusing Russians' rights.
"It is an emotional response by the State Duma, but it is an appropriate response," Putin said of the draft law.
The dispute threatens efforts by Putin and Obama to improve their relationship after presidential campaigns in both countries raised tensions between the countries.
The Kremlin says Obama is likely to visit Russia in the first half of 2013 but Western diplomats say the U.S. president will agree to a summit only if he feels progress can be made.
Asked about the conflict in Syria, another irritant in relations with Western powers that have backed opponents of President Bashar al-Assad, Putin said Moscow's main concern was the fate of the country and not that of long-time ally Assad.
He said Moscow wanted to ensure that any solution to the conflict must prevent the opposition and government forces just swapping roles and continuing to fight indefinitely.
"We are not concerned about the fate of Assad's regime. We understand what is going on there," Putin said. "We are worried about a different thing - 'what next?'"
During his first spell as president from 2000 until 2008, Putin began a tradition of giving long annual news conferences to show his grasp of policy detail. The last one, in 2008, ran for four hours and 40 minutes - slightly longer than Thursday's.
He appeared intent on Thursday on showing he has a firm grip despite protests against him that at times last winter attracted tens of thousands of people before fading after he won March's presidential election.
Critics, including in the United States and Europe, accuse him of trying to smother dissent by pushing through laws that they say can be used to stifle opponents.
But Putin said: "I cannot call it authoritarian, I cannot agree ... I think that order, discipline and following the rule of law do not contradict democracy."
However, soon after the news conference ended, federal investigators announced that protest leader Alexei Navalny had been charged with money laundering and fraud. The anti-corruption blogger already faces up to 10 years in jail on theft charges he says are politically motivated.
Critics have also said Putin would only allow Khodorkovsky, long a thorn in his side, to be freed if he was certain that he posed no political threat.
While he was addressing the news conference, a court reduced Khodorkovsky's sentence for money laundering and tax evasion from 13 to 11 years, meaning he could be freed in October 2014.
Khodorkovsky, now 49, was arrested in 2003. He had appeared to defy calls by Putin for rich businessmen not to get involved in politics by flirting with the opposition.
"There was no personal persecution," Putin said. But after his imprisonment, Khodorkovsky's Yukos oil company was broken up and sold off, mainly to the state.
Addressing question after question, Putin showed he still has a command over detail. He dismissed speculation over a back problem as rumors spread by his opponents.
Critics were scornful of his performance, particularly his remarks on democracy and the rule of law.
"'Because I love Russia.' But if you respect it too, why do you treat it like cattle?" tweeted broadcaster and commentator Yevgenia Albats.
Another Twitter user, who identified himself as Sergei Neptun, wrote: "Mr President, how much longer do we have to put up with this lawlessness in the country?"
(Additional reporting by Thomas Grove, Gabriela Baczynska and Nastassia Astrasheuskaya; Writing by Timothy Heritage; Editing by Douglas Busvine and Will Waterman)