Abbas Araghchi, Iran's Foreign Minister, participating in follow-up negotiations for the nuclear deal with the U.S. [AFP Yonhap News]

The Iranian negotiation delegation, which had reacted negatively to U.S. President Donald Trump's threatening remarks, is still engaged in follow-up negotiations for the nuclear deal with the United States, AFP reported on the 21st (local time).

An anonymous diplomatic source familiar with the negotiation situation said, "The Iranian delegation is continuing to participate in the talks and has not indicated any intention to withdraw to the mediators."

Iran's state-run IRNA news agency had reported that the negotiations, which proceeded as a four-party meeting with mediator countries Pakistan and Qatar in attendance, were adjourned after 80 minutes, and then the Iranian delegation abruptly left the negotiation venue, leading the talks to face a significant hurdle.

Earlier, President Trump had threatened to launch a strong air strike on Iran via the social media platform Truth Social that morning if Iran did not prevent the pro-Iranian armed group Hezbollah.