Bipartisan congressional skepticism toward any U.S.-Iran agreement, particularly one involving sanctions relief or economic incentives, has reinforced trader expectations that Congress will not grant formal approval in 2026. Following the June 2026 memorandum of understanding that outlined a 60-day negotiation window on nuclear issues and related matters, lawmakers from both parties demanded the text under the Iran Nuclear Agreement Review Act and signaled intent to exercise oversight or require a vote. Senate Republicans, including committee chairs, publicly criticized provisions such as financial commitments to Iran and called the interim framework inconsistent with administration goals, while broader concerns over verification, regional security, and sanctions policy persist. Ongoing tensions, including periodic military actions and incomplete implementation of the ceasefire terms, have further limited momentum for legislative consensus before year-end.