EU calls Iran nuclear talks next month
This could have shortened the deal's lifespan but Josep Borrell, the EU's diplomatic chief, who is tasked with convening meetings under the dispute mechanism, has called new talks.
Borrell said he had consulted the countries still in the deal - which also include Russia and China - and that all are determined to save the accord.
The Iran nuclear deal has been crumbling since President Donald Trump unilaterally withdrew and reimposed sanctions on Tehran, prompting the Islamic republic to announce a series of steps away from its commitments.
"Notwithstanding differences on modalities, there is agreement that more time is needed due to the complexity of the issues involved. The timeline is therefore extended," Borrell said in a statement.
"All agreed to pursue expert-level discussions addressing the concerns regarding nuclear implementation, as well as the wider impacts of the withdrawal of the United States from the JCPOA and its re-imposition of sanctions."
JCPOA is an acronym for the deal's formal title, the Joint Comprehensive Plan of Action.
Borrell said the so-called joint commission that oversees the deal and comprises representatives of all the countries involved will meet in February, though he did not give a precise date.
It usually meets in Vienna, though it can also meet in New York or Geneva.
Room for manoeuvre
Under the terms of the dispute mechanism, senior officials have 15 days from the January 14 triggering of the complaint mechanism to find a solution before deciding whether to escalate the issue to foreign ministers level.
By calling the meeting in February, Borrell has extended that initial timeline - which was conceived to solve technical complaints rather than the slow political collapse of the accord.
European officials say a certain amount of creative ambiguity was deliberately written into the text to allow room for manoeuvre in a crisis, and it now looks likely the dispute process could be prolonged for quite some time.
When they triggered the mechanism, the Europeans urged Iran to come back into full compliance with its obligations under the 2015 accord, which gave Tehran relief from sanctions in return for curbs on its nuclear programme aimed at preventing it from developing atomic weapons.
But, privately, diplomats recognise it is highly unlikely Iran will do this without substantial concessions in return - such as an end to US sanctions or Europe taking measures to offset their economic impact.
Instead they will be content if talks manage to convince Iran not to take any more steps away from the deal, giving space for back-channel diplomacy aimed at an agreement that gets both Washington and Tehran back in the game.
"We want to get round a table to work out what is the fix to get us into a stable place where things won't get worse," one diplomat said.
"It might be possible to get informal agreement on restraint."
Bomb 'not around the corner'
After repeated warnings, Germany, Britain and France triggered the dispute process on January 14 after Iran announced it would no longer observe limits on the number of centrifuges - used to enrich uranium - in its fifth step back from the deal.
But crucially Iran has said it will continue to cooperate with the International Atomic Energy Agency (IAEA) which carries out regular detailed inspections on the ground.
A western diplomat said that, for the Europeans, it was "critical that is maintained".
"The IAEA still has full access, which gives us reassurance about the activities the Iranians are doing. Agency access, verification and monitoring give us confidence that we would know if the Iranian activities are changing in nature," the diplomat said.
In-depth: Is Iran's nuclear deal still viable?
For now the Europeans are looking to get Iran back on board rather than reimposing sanctions, and they are keenly aware that they could lose control of the dispute process if it moves to the next stage - notifying the UN Security Council.
If this happens, UN sanctions automatically "snap back" after 30 days unless the Security Council votes to stop them - and here the US would be able to wield its veto.