Obama sent message ahead of deadline

US President Barack Obama recently sent a private message to Iran's leadership via Iraq's prime minister, an Iranian newspaper reported Monday on the eve of a deadline for a nuclear deal.

Hamshahri, Iran's highest-circulation daily, citing a lawmaker, said "one of the leaders of a neighbouring country" took the message from Obama to officials in Tehran.

The subject discussed was the nuclear talks between Iran and world powers led by the United States it said, without giving further details on its content.

The newspaper suggested that the message bearer was Iraqi Prime Minister Haider al-Abadi, who met Obama on June 8 on the sidelines of a G7 summit in Germany.

Abadi visited Tehran on June 17, meeting Iran's supreme leader Ayatollah Ali Khamenei as well as President Hassan Rouhani.

The newspaper also cited Abadi's visit in April to Washington where he sought arms to fight Islamic State group militants.

There was no immediate official confirmation of the report which came on the eve of today's deadline for a nuclear deal.

Meanwhile, US Secretary of State John Kerry warned yesterday it was too soon to tell if a nuclear deal with Iran is possible as he awaited the return of Iran's foreign minister from consultations in Tehran.

"We're just working and it's too early to make any judgements," Kerry told reporters in Vienna following a weekend of intense talks with counterparts from five other major powers and Iran.

In a possible sign meanwhile of progress, Russian Foreign Minister Sergei Lavrov said that he would arrive today, coinciding with the expected return of his Iranian opposite number Mohammad Javad Zarif.

French Foreign Minister Laurent Fabius, speaking in New York, said he would be back in Vienna this week. It was unclear when his British, German or Chinese counterparts might follow suit.

Over the weekend officials from both sides made clear that their deadline today to nail down a deal was highly unlikely to be met, although they said they would only extend by several days.

Zarif flew back to Tehran on Sunday night, as did many of the other ministers.

EU foreign policy chief Federica Mogherini spoke for many late Sunday when she insisted there would be no formal months-long extension, saying "postponement is not an option".

"I would say that the political will is there. I've seen it from all sides," Mogherini said, adding "we have conditions now to close the deal".

In April Iran and the P5+1 group -- the United States, China, Russia, Britain, France and Germany -- agreed on the main outlines of a deal that they hope will end a 13-year standoff over Iran's nuclear ambitions.

Under the framework, Iran will dramatically scale down its atomic activities in order to make any drive to make a weapon -- an ambition it denies having -- all but impossible.

This includes slashing the number of centrifuges enriching uranium, which can be used for nuclear fuel but also in a bomb, reducing its uranium stockpile and altering the Arak reactor.

In return, the powers have said they will progressively ease sanctions that have suffocated Iran's economy, but while retaining the option to reimpose them if Iran violates the agreement.

But turning the 505-word joint statement agreed in April in Lausanne, Switzerland into a fully-fledged, highly technical document of several dozen pages has proved hard work.

"It sounds easy. but it's difficult," German Foreign Minister Frank-Walter Steinmeier said Sunday.

Key sticking points are thought to include the pace and timing of sanctions relief, the mechanism for their "snapback" and Iran's future development of newer, faster centrifuges.