Iran will have to stop enriching uranium under any deal with the United States and could only import what is needed for a civilian nuclear program, according to U.S. Secretary of State Marco Rubio. Iran has already stated that zero enrichment is unacceptable. The U.S. is seeking to prevent Iran from developing a nuclear bomb, while Iran denies wanting to develop a nuclear weapon and insists that its nuclear program is peaceful. U.S. and Iranian officials are set to meet for a third round of talks on Tehran's disputed nuclear program.