VIENNA (Reuters) - An Iranian letter on resuming nuclear talks with world powers is ambiguous but signals "the start of opening up" from the Islamic Republic, French Foreign Minister Alain Juppe said on Thursday.
Iran handed over the letter to European Union foreign policy chief Catherine Ashton, who handles contacts with Tehran on behalf of the six major powers, on Wednesday.
"Madame Ashton received a letter from Mr (Iranian chief nuclear negotiator Saeed) Jalili responding to her letter in October last year," Juppe told reporters during a visit to Vienna.
"In our eyes it remains ambiguous, but constitutes the start of opening up from Iran which says it is ready to talk about its nuclear program."
Iran's sincerity would be tested when a senior U.N. nuclear watchdog team holds a second round of talks in Tehran on February 20-21, Juppe said. The first round late last month produced no concrete outcome, diplomats in Vienna have said.
"And if Iran is really ready to discuss and show its sites and documents (as requested by U.N. investigators), then the conditions will be there to restart negotiations," Juppe said.
He made clear that Iran must make a first step, without preconditions, towards resolving suspicions it is seeking atomic bombs, before any easing of sanctions, which the United States and its European allies have ratcheted up in recent months.
"For France lifting sanctions would not be a precondition. It is up to Iran to show its goodwill first," Juppe added.
Iran has repeatedly rejected U.N. Security Council demands that it halt uranium enrichment, which can have both civilian and military purposes.
Tehran denies Western accusations its nuclear program is aimed at developing a weapons capability, saying it is for peaceful electricity generation only.
(Reporting by John Irish and Fredrik Dahl; Editing by Mark Heinrich)