All parties to the 2015 nuclear deal with Iran want to safeguard the accord and strongly oppose Washington’s decision to unilaterally re-impose sanctions on Tehran, the head of the Chinese delegation said after a meeting of the pact members.

The remaining parties to the deal - Britain, France, Germany, Russia, China, the EU and Iran - met for emergency talks in Vienna called in response to an escalation in tensions between Iran and the West in the past month that included confrontations at sea and Tehran’s breaches of the accord.

“All sides have expressed their commitment to safeguard the JCPOA and to continue to implement the JCPOA in a balanced manner,” Fu Cong, director general of the Department of Arms Control at China’s Foreign Ministry told journalists after the meeting in Vienna.

“All sides have expressed their strong opposition against the US unilateral imposition of sanctions,” he added.

Senior Iranian nuclear negotiator

Abbas Araqchi said the talks were “constructive,” but said Tehran would continue to reduce its nuclear commitments if Europeans failed to salvage the pact.

“The atmosphere was constructive. Discussions were good. I cannot say that we resolved everything, I can say there are lots of commitments,” Araqchi said. “As we have said, we will continue to reduce our commitments to the deal until Europeans secure Iran’s interests under the deal,” Araqchi said after the meeting.

Iran has called on Europe to accelerate its efforts.

“All our steps taken so far are reversible if other parties to the deal fulfil their commitments,” an Iranian diplomat said before the meeting was due to start.

In response to the sanctions, Iran said in May it would decrease its commitments under the nuclear pact.

Under the deal, most international sanctions against Tehran were lifted in return for limitations on its nuclear work.

So far, Iran has breached the limit of its enriched uranium stockpile as well as enriching uranium beyond a 3.67 per cent purity limit set by its deal with major powers, defying a warning by Europeans to stick to the deal despite US sanctions.

The UN nuclear watchdog, policing the deal, has confirmed the measures announced by Tehran.

The meeting in Vienna comes after Iran’s elite Revolutionary Guards seized a British-flagged oil tanker on July 19, two weeks after British forces captured an Iranian oil tanker near Gibraltar which it said was violating sanctions on Syria.

Araqchi said Britain’s seizure of the Iranian oil tanker was a violation of the nuclear pact.

“We witnessed the seizure of an oil tanker carrying Iranian oil in the Strait of Gibraltar which in our view is a violation of (the nuclear deal),” Araqchi said.

“And the countries who are part of (the nuclear deal) shouldn’t create obstacles for the export of Iranian oil.”

Britain has called for a European-led naval mission to ensure safe shipping through the Strait of Hormuz, a vital international oil shipping route.

An Iranian government spokesman said on Sunday such a mission would send a “hostile message.” Britain said on Sunday Royal Navy destroyer HMS Duncan had arrived in the Gulf to join a British frigate escorting British-flagged ships through the Strait.

Iran has threatened to disrupt oil shipments through the waterway, where several oil tankers have been attacked, if the United States tries to strangle its economy with sanctions on its vital oil exports.

Oman and Iran were cooperating on navigation through the Strait of Hormuz, Oman’s minister in charge of foreign affairs said on Sunday after meeting Iranian officials in Tehran.

Yousuf Bin Alawi Bin Abdullah added that there is a need for all parties to maintain contact to avoid more incidents in the world’s busiest shipping lane, speaking in an interview with Omani state TV.

Separately, Iranian President Hassan Rouhani said on Sunday he hoped British Prime Minister Boris Johnson’s “familiarity” with the Islamic Republic will help improve relations between Iran and Britain.

In a message posted on the official Iranian presidency website, Rouhani congratulated Johnson on his appointment.

Agencies