Satellite imagery from June 9, 2025 showed an unusual convoy at the entrance to an underground nuclear complex near Isfahan. The convoy contained a flatbed truck carrying 18 large, sealed barrels in a configuration which experts said is consistent with the transport of hazardous or sensitive material. Some analysts theorized that the barrels may have contained highly enriched uranium or other materials used in the nuclear fuel cycle, while others raised the possibility of deliberate signaling or deception by Iran. The timing of the delivery days before Israeli airstrikes on Iranian nuclear facilities suggests Iran may have moved key nuclear assets ahead of the strikes.

The United States can be certain that it has destroyed approximately one-third of Iran's missile arsenal in the ongoing war, according to sources familiar with relevant U.S. intelligence. Another third has likely been damaged or buried in underground facilities where it is inaccessible. One of the sources claimed U.S. intelligence also indicates that one-third of Iranian drone capability can be assessed with certainty to have been destroyed. A Pentagon official stated that Iranian drone and missile attacks have decreased by about 90% since the start of the war. A senior Israeli military official claimed that more than 335 Iranian missile launchers comprising 70% of Iran's missile launch capacity have been destroyed. On March 26, Iran launched 15 ballistic missiles and 11 drones at the United Arab Emirates (UAE), according to the UAE's defense ministry.

Iran launched two intermediate-range ballistic missiles at the joint U.S.-U.K. Diego Garcia military base in the Indian Ocean, according to multiple U.S. officials. One missile failed in flight and the other failed to reach its target after a U.S. warship fired an interceptor missile at it. Diego Garcia is approximately 2,500 miles (4,000 kilometers) from Iran. Iran has previously claimed to have limited the maximum range of its missiles to 1,250 miles (2,000 kilometers).

The latest round of U.S.-Iran negotiations ended without a deal. U.S. negotiators demanded that Iran dismantle its nuclear facilities at Fordow, Isfahan, and Natanz and turn over its remaining enriched uranium stockpile to the United States, and they insisted that the terms of any deal have no expiration. Iran rejected transferring its enriched uranium abroad and objected to ending enrichment, destroying nuclear sites, or permanent limits on its nuclear program. Iran proposed reducing its enrichment level to 1.5%, pausing enrichment for a period of years, or enriching uranium through an Arab-Iranian consortium based in Iran. The United States may consider allowing Iran to enrich a limited amount of uranium for its research reactor in Tehran, according to U.S. officials. The talks took place in Geneva and were mediated by Oman's foreign ministry, which said technical experts would continue to negotiate in Vienna the following week. Meanwhile, an additional destroyer joined the U.S. fleet in waters near Iran, and a U.S. aircraft carrier approached the Eastern Mediterranean. U.S. Secretary of State Marco Rubio said Iran's refusal to discuss its ballistic missile program was a major problem for the United States.