Iranian Foreign Minister Mohammad Javad Zarif stepped down on Monday, February 25, announcing his resignation on Instagram, Al Jazeera reports.

"I am apologising you for all the shortcomings ... in the past years during my time as foreign minister ... I thank the Iranian nation and officials," he wrote on his Instagram page.

There was no immediate reason giving for the resignation, which can only take effect if President Hassan Rouhani accepts it.

Iran's state-run IRNA news agency cited a spokesman, Abbas Mousavi, confirming Zarif had resigned.

Zarif was appointed minister of foreign affairs in August 2013, two years before Iran agreed to scale back its uranium enrichment programme and pledged not to develop nuclear weapons in return for the lifting of international sanctions as part of a landmark nuclear deal brokered with the United States, the UK, France, Germany, Russia, China and the European Union.

A vocal supporter of the deal, Zarif has since come under pressure from more hardline power blocs within the Islamic Republic who were opposed to the agreement, formally known as the Joint Comprehensive Plan of Action (JCPOA).