Reuters nonetheless indicates that both sides have stated that there was some headway, but they were apparently not forthcoming about the specific content of this headway. One clue comes from the Associated Press, which reported that Iranian diplomats appeared to be considering a new proposal offered by the US, which would allow the Islamic Republic to keep much of its uranium enrichment infrastructure, but further reduce its stockpile of nuclear material. If such an agreement materialized, it would entail sending some of that material to Russia, a perennial Iran ally and a current source of Iran’s imported uranium.

But in spite of reports that this proposal is being considered, it is not clear what its chances are of final approval. Supreme Leader Ayatollah Ali Khamenei has final authority over any deal, as well as all other matters in the Islamic Republic. He has maintained a hard line concerning the nuclear issue, declaring, among other things, that his negotiators can accept no “imposition from the other side,” and may not agree to any reduction in Iran’s enrichment capability. If this latter demand were conceded, it would allow Iran to swiftly replace any low-enriched uranium that it shipped out of the country.

Further reports have indicated that Thursday’s talks did not resolve the question of whether an extension of the November deadline might be sought. Both sides have issued vague statements indicating that such an extension remains a possibility until a final agreement is formed. But Iran, at least, has been inconsistent about whether it will actively pursue an extension. Foreign Minister Mohammad Javad Zarif said on Thursday that Tehran explicitly opposes an extension, according to the AFP. But this comment comes only one day after Zarif himself said that more time might be needed, and only about a week after Deputy Foreign Minister Abbas Araqchi said that an extension was already part of the agenda.

Implied support for an extension has also been offered by President Hassan Rouhani, who said that a nuclear deal is certain at this point, whether it is reached before or after the November 24 deadline. Some critics of the talks or of the Iranian regime suggest that an extension is Iran’s best case scenario, in that it allows officials to avoid having to sell concessions to conservatives, while also letting them continue working to acquire economic support from foreign countries in order to weaken sanctions that have been temporarily alleviated as part of the negotiating process.