British Royal Navy patrol vessel guards the oil supertanker Grace 1
British Royal Navy patrol vessel guards the oil supertanker Grace 1Reuters

Iran on Sunday called Britain's seizure of an Iranian oil tanker in the Persian Gulf a breach of the 2015 nuclear deal with world powers.

The UK and Gibraltar seized the Iran-flagged tanker Grace 1 in early July. British authorities said the tanker was attempting to transport oil to Syria, a violation of EU sanctions.

Iran, in turn, seized the British-flagged Stena Impero a week later. However, Iranian Foreign Minister Mohammad Javad Zarif denied the move was an act of revenge for the capture of the Iranian tanker, claiming Iran had taken measures against the ship to implement international law.

In comments to journalists after a meeting in Vienna with the remaining signatories to the nuclear deal, Iranian Deputy Foreign Minister Abbas Araghchi linked the tanker row to discussions over the deal.

"Since Iran is entitled to export its oil according to the JCPOA, any impediment in the way of Iran's export of oil is actually against the JCPOA," Araghchi said, according to AFP.

He added that the issue of Iran's oil exports -- including US attempts to prevent them completely -- was raised at the meeting.

"I think the atmosphere was constructive and the discussions were good, I cannot say that we resolved everything," he said.

Envoys from Britain, France, Germany, China, Russia and Iran had gathered for talks in the Austrian capital, a month after a similar meeting failed to achieve a breakthrough.

The future of the 2015 has been in jeopardy ever since US President Donald Trump withdrew from it last May, and later imposed two rounds of sanctions on Iran, the latest of which went into effect in November of 2018.

The European signatories to the 2015 deal – including Britain – did not agree with Trump’s decision to leave the agreement and vowed to help Iran evade the economic sanctions imposed by the US, shielding companies doing business with the rogue state in an effort to preserve the Iran nuclear deal.