Iran 's president formally approved the resignation of one of his vice presidents who served as Tehran's key negotiator in its 2015 nuclear deal with world powers, just as the head of the United Nations' nuclear watchdog was due to arrive in the Islamic Republic on Wednesday.

Reuters reported, citing Iranian state media, that the second round of talks between the USA and Iran concerning the nuclear program will take place on April 19 in Rome. It was announced that mediators from Oman will participate in the meeting.

Make Iran dismantle its nuclear and missile programs. Then its top negotiator started softening his tone, and had to retreat.

The recent U.S. deployment of B-2 bombers, the only planes able to launch the most powerful bunker-busting bombs, to within range of Iran is a potent signal to Tehran of what could happen to its nuclear programme if no deal is reached to rein it in.