The international community was weighing its options after Iran responded to an offer aimed at ending a long-running nuclear standoff with a call for "serious talks" but no indication it would freeze uranium enrichment as demanded by the UN Security Council. Europe said Iran's response, delivered Tuesday, required careful analysis as signs of a split began to emerge among world powers over how to respond, with the United States pressing for sanctions and China appealing for patience.
Iran's top nuclear negotiator Ali Larijani said Tehran was ready for "serious talks" but no details were made public of its response to a package of incentives offered by world powers in return for a moratorium on enrichment by an August 31 UN deadline.
However, all indications ahead of Iran's submission were that it would not stop enrichment, a process which can be used to fuel nuclear reactors or extended to create the core of an atomic weapons.
Washington suspects the nuclear program is a cover for an attempt to produce a bomb. However, Iran, the world's fourth largest oil producer, insists it is purely for peaceful power generation.
Iran's supreme leader Ayatollah Ali Khamenei, who has the last word on all key policy issues, said Monday that Iran was determined to press ahead with its nuclear program.
And Atomic Energy Organization deputy head Mohammad Saeedi also said Tehran would "provide Europe with an exceptional chance for... a return to the negotiating table," but insisted an enrichment freeze was "no longer possible."
Tehran gave the written response to representatives of the five permanent Security Council members plus Germany which drew up the package of trade and technology incentives.
"Iran is ready for serious talks with the 'five plus one' group from August 23 over the offered package," the student news agency ISNA quoted Larijani as telling the envoys.
"We prepared the response to the package with a positive view and even tried to open a way for fair talks by interpreting the many cases of ambiguity logically and positively."
He called on the world powers to return to negotiations but made no direct reference to the August 31 deadline for Iran to freeze enrichment or risk UN sanctions.
Even in the absence of details, the United States began urging punitive action while China said sanctions were not the way to resolve the international concerns about the purpose of Iran's nuclear program.
"We will obviously study the Iranian response carefully," US ambassador to the United Nations John Bolton said Tuesday.
"But we are also prepared -- if it does not meet the terms set -- to proceed here in the Security Council ... with economic sanctions.
The White House also warned that a nuclear-armed Iran would be "dangerous" to the world, but declined to assess Tehran's reply.
US President George W. Bush made clear on Monday that he believes Iran continuing with the nuclear program "would be a mistake, and dangerous for the region and the whole world," a spokeswoman said.
A Chinese official said Beijing opposed sanctions.
"We have all along stood for a peaceful settlement of the issue through negotiations, rather than resorting to force or threatening sanctions," said Sun Bigan, special envoy to the Middle East.
"Resorting to force and sanctions cannot fully solve the problems."
EU foreign policy chief Javier Solana said "the document is extensive and therefore requires a detailed and careful analysis" and that he would remain in open contact with Larijani.
Inspectors from the International Atomic Energy Agency faced obstacles carrying out their work at Iranian nuclear facilities in recent days although these were not yet "deemed to be systematic and obstructionist," a diplomat close to the UN nuclear watchdog told AFP.
But Saeedi said reports of UN inspectors being blocked were "inaccurate."
The Iran crisis has caused jitters in oil markets since the OPEC member threatened to halt exports to the West if sanctions are imposed.
But oil prices dropped slightly in Asian trade Wednesday, with Brent North Sea crude for October delivery dropping 12 cents to 73.12 dollars a barrel.
