Iran has long accused Israel of targeting its nuclear program through covert operations. Israeli officials, in turn, have hinted at potential strikes on Iran's nuclear sites. This exchange of threats that has intensified amid ongoing hostilities between the two nations since Israel's attacks on Hezbollah, a long-standing ally.

Rafael Mariano Grossi of the IAEA was visiting Tehran in an effort to restore his inspectors' access to Iran's program and answer still-outstanding questions over it, as he has on previous trips with limited success since Trump unilaterally withdrew the U.S. from the Islamic Republic's nuclear deal with world powers.

Rafael Grossi, head of the International Atomic Energy Agency, the U.N. nuclear watchdog, says the window of opportunity to diplomatically engage with Iran is beginning to "shrink."