Top Iranian and U.S. negotiators will meet again in Oman to discuss a new nuclear deal, while President Trump expresses confidence in reaching an agreement. Talks will begin at the expert level to establish a framework for a potential deal. Trump has threatened military action if diplomacy fails. Iran is willing to negotiate some curbs on its nuclear work in exchange for the lifting of sanctions, but maintaining its enrichment program and missile capabilities are non-negotiable. European states suggest that a comprehensive deal should also include limits on Iran's ballistic missile capabilities.