An emergency meeting between parties to Iran's 2015 nuclear deal in Vienna was constructive but there were some issues left unresolved, Iranian official Abbas Araqchi said on Sunday.
“The atmosphere was constructive. Discussions were good. I cannot say that we resolved everything, I can say there are lots of commitments,” Mr Araqchi, the senior Iranian nuclear negotiator, told reporters after the meeting.
Diplomats from the signatories of the 2015 nuclear deal - including Britain, China, France, Germany and Russia - met with Iranian officials on Sunday to try and de-escalate tensions between Tehran and the West. In the last two months, there have been several maritime conflicts in the region and Iran has breached terms of the accord by increasing its uranium enrichment levels above the level agreed in the pact.
“As we have said, we will continue to reduce our commitments to the deal until Europeans secure Iran’s interests under the deal,” Mr Araqchi said.
Sunday's meeting was a bid to salvage the accord that has been severely damaged by the United States' withdrawal last year.
In retaliation to the US withdrawal, Iran said in May it would disregard certain limits the deal set on its nuclear programme and threatened to take further measures if remaining parties to the deal, especially European nations, did not help it circumvent the sanctions.
The US said it brought down one and possibly two Iranian drones this month, and blamed Tehran for a series of attacks on tanker ships.
Iran shot down an unmanned US aircraft in June, after which US President Donald Trump announced that he had called off retaliatory air strikes at the last minute because the resulting death toll would have been too high.
The US and Saudi Arabia have accused Iran of being behind several attacks on tankers in the Gulf of Oman in June, which Iran denies.
On July 19, a British-flagged tanker was impounded by Iran's Revolutionary Guards with its 23 crew aboard in the Strait of Hormuz.
The seizure was seen by London as a tit-for-tat move for British authorities detaining an Iranian tanker off the UK overseas territory of Gibraltar early this month.
Efforts by European powers, notably France's President Emmanuel Macron, to salvage the nuclear deal have so far come to nothing.
The remaining signatories have pledged to work towards a breakthrough at a future ministerial meeting, for which no date has yet been fixed.
Referring to the need for a "preparatory meeting before the ministerial level meeting that will be necessary", one European diplomat told AFP it was "imperative to talk to the Iranians after the proven violations of their commitments".
The European Union said earlier this week the extraordinary meeting would be chaired by the secretary general of the European External Action Service, Helga Schmid.
It said the talks were requested by Britain, France, Germany and Iran and would examine issues linked to the implementation of Joint Comprehensive Plan of Action, under which the 2015 deal is implemented.
The talks come on the same day that Iran slammed as "provocative" a British proposal for a European-led naval mission to escort tankers in the Gulf.
"We heard that they intend to send a European fleet to the Persian Gulf which naturally carries a hostile message, is provocative and will increase tensions," government spokesman Ali Rabiei said, quoted by ISNA news agency.
Britain said on Monday it was planning a European-led force for shipping in the Gulf in response to Iran's seizure of the Stena Impero.
In his comments on Sunday, the Iranian government spokesman said Iran believed the security of the oil-rich Gulf had to be maintained by countries in the region.
"We are the biggest agent of maritime security in the Persian Gulf," said Mr Rabiei.
