With foreign ministers of the five countries still supporting the deal due to meet their Iranian counterpart on Friday, here is a look back over developments since Trump's decision.

- Washington quits -

Trump pulls the United States out of the landmark nuclear pact on May 8, reinstating Washington's sanctions on Iran and companies with ties to the Islamic republic.

"The Iran deal is defective at its core," he says in a televised address.

Tehran's regional rivals Saudi Arabia and Israel applaud Trump's decision.

But Britain, France and Germany swiftly say they are "determined" to save the nuclear deal and its economic benefits for Iran.

President Hassan Rouhani warns Iran could resume uranium enrichment "without limit" if negotiations with Europe, Russia and China on saving the accord do not produce positive results.

- Diplomatic marathon -

On May 12 Foreign Minister Mohammad Javad Zarif says Iran is preparing to resume "industrial-scale" uranium enrichment "without any restrictions", unless Europe provides solid guarantees to maintain trade ties reinstated under the deal.

He starts a diplomatic tour the next day to save the accord.

On May 16 the European Union launches work on an economic plan to keep the Iran nuclear deal alive.

- 'Strongest sanctions' -

Washington warns on May 21 that Iran will be hit with the "strongest sanctions in history" unless it abides by stricter controls on its nuclear programme.

On May 24 the UN's nuclear watchdog, the IAEA, says Iran continues to respect the terms of the 2015 accord.

A day later, in Vienna, signatories of the nuclear deal meet without the United States in a bid to save the agreement.

On May 30 the United States places several Iranian state groups on its sanctions blacklist, accusing them of serious human rights abuses and censorship.

- Iran to boost capacity -

On June 4 Iran notifies the IAEA that it has launched a plan to increase its uranium enrichment capacity.

The following day Israeli Prime Minister Benjamin Netanyahu claims this is aimed at producing nuclear weapons to be used against his country.

- Attack foiled in France -

On June 30 authorities say they have foiled an alleged plot to bomb a rally by an exiled Iranian opposition group based in France also attended by leading US figures.

Six people are arrested in Belgium, France and Germany.

The opposition group says the Iranian regime is behind the alleged plot.

Tehran dismisses it is a "false flag", designed to overshadow an upcoming trip by Rouhani to Europe.

The Iranian president arrives in Switzerland on July 2, for a European trip billed as of "prime importance" by his government.

- Strategy 'zero' -

A top US official says on July 2 that Washington is determined to force Iran to change its behaviour by cutting its oil exports to zero, confident the world has enough spare oil capacity to cope.

US secondary sanctions on firms dealing with Iran would "snap back" in August for trade in cars and metals and in November for oil and banking transactions, the State Department official says.

Rouhani responds on July 3 saying the United States can never prevent Iran from exporting its oil and Washington's goal is a "baseless fantasy".

Iran's official IRNA news agency announces that the foreign ministers of Iran and the world powers still party to the 2015 deal with meet in Vienna on Friday, to discuss an "incentive package" aimed at persuading Iran to stay in the agreement.