Britain's seizure of an Iranian oil tanker in Gibraltar is a violation of the 2015 nuclear deal, Abbas Araqchi, a senior member of the team who negotiated the deal and a deputy foreign minister, said on Sunday, according to the ISNA news agency.

"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."