Top EU diplomat Josep Borrell was Monday due to visit Iran, said officials in Tehran and Brussels, on his first trip there since taking office, aiming to reduce rising tensions over the Islamic republic’s nuclear programme. The 2015 nuclear deal between Tehran and a group of world powers has been crumbling since US President Donald Trump withdrew from it in 2018, and Washington has since stepped up sanctions and a campaign of “maximum pressure” against Iran. Tehran has gradually stepped back from its own commitments under the deal, while military tensions with the United States have brought the arch foes to the brink of full-blown confrontation in recent weeks.