U.S. says reviewing Iranian letter on nuclear talks

WASHINGTON (Reuters) - The White House offered a cautious response on Thursday to an Iranian letter to world powers on resuming talks about its nuclear program, but made clear it was open to renewed diplomacy if Tehran was committed to reducing tensions with the West.

"It could lead to further diplomacy, provided that they're serious about it," said a senior admininstration official. "We have made clear that this has to be a dialogue about their nuclear program specifically."

Iran, hammered by international sanctions, delivered the letter on Wednesday to European Union foreign policy chief Catherine Ashton, who handles contacts with Tehran on behalf of the six major powers. The correspondence was a response to a letter sent to Tehran by Ashton in October.

"We're reviewing the letter," said White House press secretary Jay Carney. "The Iranians needed to respond to that (October) letter and so they have, but I don't want to make any qualitative judgements about their response at this time," he told reporters travelling with President Barrack Obama.

The West accuses Tehran of using its nuclear program to pursue weapons capability and has slapped sanctions on the country's oil industry which have hit the wider economy hard.

Iran rejects the charge and insists its program is purely for peaceful nuclear power generation purposes.

"There is time and space here for a diplomatic solution to this, if Iran chooses to engage in constructive behaviour," Carney said. Defense Secretary Leon Panetta, in a separate statement, stuck closely with that line.

"We have always maintained that it's in our interest to try to resume talks with Iran - assuming that those talks are constructive," he said, adding Washington would consult with its partners about any "next steps".

Obama earlier this month emphasized his desire for a diplomatic solution to the stand-off, highlighting the harm that a conflict in the Gulf could do to oil prices, as well as U.S. troops stationed in Afghanistan, which borders Iran.

(Reporting By Laura MacInnis, Matt Spetalnick and Phil Stewart; Writing by Alister Bull; Editing by Sandra Maler)