In the telephone conversation on Saturday, held at the request of Raab, Zarif reiterated the need for the full removal of the illegal and unfair US sanctions against Iran in such a way that the Islamic Republic would be able to verify their termination.
Only in that case will Iran resume honoring the JCPOA commitments, Zarif said.
The Iranian foreign minister also called on the European parties to the JCPOA to fulfill their commitments under the deal and take part in the Vienna meeting constructively.
For his part, Raab said the UK will make efforts for the fruitfulness of the forthcoming JCPOA negotiations.
The two senior diplomats also talked about a series of political and consular affairs between Tehran and London.
Following the 18th meeting of the JCPOA Joint Commission that was held via videoconference on Friday, the participants decided to proceed with the talks in Vienna next week to continue the consultations and define the measures relating to the termination of US sanctions.
The JCPOA was signed in 2015 between Iran and the Group 5+1 and endorsed by the UN Security Council Resolution 2231.
However, then-US president Donald Trump unilaterally pulled Washington out of the nuclear deal in May 2018 and reinstated the anti-Iranian sanctions that had been lifted by the deal.
As the remaining European parties have failed to fulfill their commitments to the accord and compensate for Washington’s absence, Iran moved in May 2019 to scale back its JCPOA commitments.