Iran has proposed a three-stage nuclear deal to the US, offering to cap its uranium enrichment at the same levels as the 2015 deal in exchange for the lifting of US sanctions. The proposal includes temporary decreases in enrichment, the lifting of sanctions, and the resumption of inspections by the International Atomic Energy Agency. In the final stage, Iran would transfer enriched uranium stockpiles to a third country and the US Congress would approve the deal. However, sources suggest that Iran's Supreme Leader agreed to the talks to buy more time to rebuild its air defenses and restore its missile production capacity.