Katherine Wells, Ben Rezaei, Ria Reddy, Alexandra Braverman, Avery Borens, Ben Schmida, Kelly Campa, Victoria Penza, and Annika Ganzeveld

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Iran and the United States continue to disagree on the US demand for zero uranium enrichment, which may stall the US-Iran nuclear negotiations and delay a nuclear deal. US President Donald Trump stated on May 15 that the United States and Iran are "very close" to reaching a nuclear deal and that Iran has “sort of” agreed to US demands. An unspecified Iranian source familiar with the negotiations told Reuters on May 15 that Iran and the United States continue to disagree on the issue of Iranian uranium enrichment. Senior US officials, including lead US negotiator Steve Witkoff, have previously stated that Iran can “never” have an enrichment program. Senior Iranian officials have repeatedly rejected this US demand. Iranian Supreme Leader Adviser Ali Shamkhani told NBC News on May 14 that Iran is ready to sign a deal with the United States and willing to limit enrichment to “civilian levels." "Civilian levels" likely refers to the 3.67 percent enriched uranium limit set by the 2015 Joint Comprehensive Plan of Action. Reuters reported that the United States and Iran also disagree on where and how Iran would transfer its highly enriched uranium stockpile to another location, citing unspecified Iranian sources. Iran's rejection of the US demands for zero uranium enrichment may jeopardize the talks or force negotiations toward a less expansive agreement than what the United States reportedly desires.

Key Takeaways:

• Activity in the Persian Gulf: An Iranian vessel may have harassed a commercial vessel in the Persian Gulf on May 10. The United Kingdom Maritime Trade Operations reported that a small craft collided with a merchant vessel and attempted to collide with other vessels about 80 nautical miles northwest of Jebel Ali, the United Arab Emirates. It is unclear if the collision was intentional or an accident. The incident occurred west of Siri Island, which Iran controls. This incident occurred shortly before Iranian Armed Forces General Staff Chief Major General Mohammad Bagheri ordered the deployment of missile-capable fast attack craft (FAC) to Iranian islands in the Persian Gulf on May 12. Bagheri stated on May 12 that Iran would retaliate against US military bases, disrupt international commercial shipping, and attack regional states hosting US forces "if the US military makes a mistake.”

• US-Iran Nuclear Negotiations: Iran and the United States continue to disagree on the US demand for zero uranium enrichment, which may stall the US-Iran nuclear negotiations and delay a nuclear deal. US President Donald Trump stated on May 15 that the United States and Iran are "very close" to reaching a nuclear deal and that Iran has “sort of” agreed to US demands. An unspecified Iranian source familiar with the negotiations told Reuters on May 15 that Iran and the United States continue to disagree on the issue of Iranian uranium enrichment. Senior US officials, including lead US negotiator Steve Witkoff, have previously stated that Iran can “never” have an enrichment program. Senior Iranian officials have repeatedly rejected this US demand.

• US-Houthi Ceasefire: The Houthis are unlikely to seriously engage in the Saudi-led peace roadmap because doing so would undermine their objectives to control all of Yemen. UK-based outlet Amwaj Media reported on May 13 that the United States asked the Houthis to return to the peace process, which Saudi Arabia initiated in 2022, as part of the US-Houthi ceasefire. CTP-ISW assessed on May 9 that the Houthis have little incentive to participate meaningfully in peace negotiations given that the Houthis have not suffered any military defeats that would compel them to re-engage in peace talks. Amwaj Media separately reported on May 13 that the Houthis have agreed to release United Nations (UN) employees that the group has taken hostage as part of the ceasefire agreement, according to several Yemeni sources with knowledge of the US-Houthi ceasefire process.

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