ANALYSIS-Russian energy ties with Iran send U.S. a message

By Simon Webb and Amie Ferris-Rotman

DUBAI/MOSCOW, Feb 21 (Reuters) - As the United States warns the world away from business with Tehran, Moscow's tightening ties to Iran's energy sector underline Russia's differences with Washington over Iranian nuclear plans and Kosovo's independence.

While the timing of Moscow's announcement on Tuesday may have been political, the deal for Russian state-controlled energy giant Gazprom GAXP.MM to take on big new Iranian oil and gas projects was a long time in the making and dovetails with Gazprom's strategic ambitions, analysts said.

Gazprom, the world's biggest gas producer, will play a larger role in developing Iran's giant South Pars gas field and will also drill for oil.

"The Russian government and the United States are at loggerheads over how to engage with Iran, with Russia actively favouring a more open relationship," said Ronald Smith, chief strategist at Alfa Bank. "This makes Gazprom rather indifferent to American policy wishes."

The U.S. accuses Iran of using uranium enrichment to develop weapons, while Tehran says it needs nuclear power. Russia has been reluctant to impose more U.N. sanctions on Iran.

Despite voicing its own concerns about Tehran's ambitions, Moscow is building Iran's first nuclear power plant and has supplied the fuel it will use.

Russia opposes Kosovo's split from Serbia, which the U.S. has backed. Despite growing clout on the world stage, Moscow has proved powerless to prevent Kosovo announcing its independence this week.

"There is probably a political element given what happened last week in Kosovo," said Chris Weafer, chief strategist at UralSib bank.