The talks aimed to follow up on a package of political, security, and economic incentives offered unsuccessfully to Iran in 2006.
After the meeting, Chinese Assistant Foreign Minister He Yafei told reporters that the participants agreed "on the main content of a plan" to restart the lapsed nuclear negotiations with Iran. But he cautioned that "not all" problems had been resolved.
He did not go into any detail on what differences remain. But he said the officials will report back to their governments, and as soon as the oustanding issues are resolved, the proposals will be referred to the Iranian side.
The meeting involved the United States, Russia, Britain, France, and Germany, as well as China itself. A European Union representative was also present.
He Yafei said earlier, before the talks began, that the participants were determined to press ahead. "So, we are here today to discuss new developments surrounding the Iran nuclear issue," he said. "We are certain that we have agreed to continue our discussion on the proposals on resuming talks on the Iranian nuclear issue."
Tehran has spurned the aid offer, and for years has said it will never give up the independent ability to enrich uranium, which it is now developing. The international community fears that Iran may intend to put its enrichment capacity to military use, something which Tehran denies. The UN Security Council has imposed three sets of international sanctions against Iran in a bid to get it to obey resolutions ordering it to stop enrichment activity.
Iran is continuing its defiance of the UN, however, announcing only last week that it plans to install 6,000 more high-speed centrifuges at its Natanz uranium-enrichment plant.
Adding to the sense that Iran is in no mood to compromise was the cancellation without explanation of a meeting set for April 14 between Iran's top nuclear official, Gholamreza Aghazadeh, and the head of the International Atomic Energy Agency (IAEA), Muhammad el-Baradei. El-Baradei was hoping to persuade the Iranians to allow his agency to make further investigations into Iran's alleged past program for nuclear weapons development.
The IAEA chief will however be discussing the "Iran dossier" in Berlin on April 17 with German Foreign Minister Frank-Walter Steinmeier. His ministry said the two will also look at nuclear nonproliferation issues. They can also be expected to review what, if anything, transpired at the April 16 Shanghai meeting.
China has taken something of a diplomatic gamble in hosting this gathering. Previously, it has stayed on the sidelines of the debate on Iran's nuclear program, joining the UN sanctions drive only reluctantly. Chinese officials want to avoid offending Iran, which is China's third-biggest supplier of oil, while at the same time they do not want to offend the United States, which seeks stronger action against Iran.
For this reason, it has chosen to host the talks on a subject that has become a mere side issue -- namely, should the benefits package already offered be extended in scope. Given Tehran's repeated rejection of the package, it's hard to believe it would react positively to any likely sweetening of the offer.
THE COMPLETE PICTURE: RFE/RL's complete coverage of controversy surrounding Iran's nuclear program.
An annotated timeline
of Iran's nuclear program.