Tehran, Mar 8 (IANS): Iran's top security official on Monday urged all parties involved in nuclear talks in Austria's capital Vienna to put forward "initiatives" to accelerate the conclusion of the nuke deal.

"Prospect of a deal in Vienna talks remains unclear due to Washington's delay in making a political decision," Secretary of Iran's Supreme National Security Council Ali Shamkhani tweeted, Xinhua news agency reported.

Shamkhani said that the priority of Iranian negotiators is to resolve the remaining issues that are considered to have crossed the red line of the country.

"Rapid access to a strong deal requires new initiatives from all parties," he noted.

Iran and the remaining parties to the 2015 nuclear deal, formally known as the JCPOA, are currently involved in negotiations in Vienna seeking ways to settle disputes about the revival of the JCPOA.

Reports from Vienna suggest that the negotiators are "close" to an agreement with a few key issues remaining which require "political decisions" of the parties.