PRESIDENT Vladimir Putin has supported a ban on Americans adopting Russian children in a feud over a US human rights law which, he said, was poisoning relations.

Mr Putin, 60, struck a hawkish tone in his first annual news conference since he began a new six-year term in May.

But he denied tough measures against his opponents since his return to the Kremlin meant he was an authoritarian leader.

He used the marathon live broadcast to dismiss speculation about his health, underline the strength of the economy and portray himself as the guarantor of stability.

"This is by no means the least successful period in Russia's history," he said.

"Because I love Russia, without irony, I look forward to any future president being more successful."

In front of 1200 journalists in a Moscow conference centre, Mr Putin was calm, rarely smiled and was still going after three hours. He was animated when asked about the row with Washington.

He described as "unfriendly" a law signed by President Barack Obama last week that will punish Russians accused of violating human rights by refusing them visas and freezing their assets in the US.

"This, of course, poisons our relationship," he said of the measures, drawn up because of concern over the death in a Russian prison of anti-corruption lawyer Sergei Magnitsky in 2009.

Mr Putin signalled he would sign into law a tit-for-tat move proposed by Russia's parliament to prevent Americans adopting Russian children as well as barring entry to US citizens accused of abusing Russians' rights.

l A Russian court has cut two years off former oil tycoon Mikhail Khodorkovsky's 13-year jail sentence for embezzlement, clearing the way for one of Mr Putin's fiercest critics to walk free in October 2014. Khodorkovsky's business partner Platon Lebedev also had his term cut by two years