Before lifting sanctions, the United States and its European allies want Iran:
To prove that it does not have a military nuclear program by allowing agency inspectors full access to all Iranian sites. Tehran has barred inspectors from talking to key nuclear scientists.
To remove preconditions to talks. In January, Tehran demanded that sanctions first be lifted and that the West recognize Iran's "right to enrich."
To export the uranium it has enriched to 20 percent, probably in return for nuclear fuel made elsewhere.
To close its Fordo plant.
To negotiate how to deal with a larger stockpile of low-enriched uranium.
April 13-14: The five permanent members of the U.N. Security Council, plus Germany and Iran, are to meet in Istanbul for a new round of talks over Tehran's nuclear program.
June 28: A U.S. provision begins that imposes sanctions on any foreign company that continues to engage in oil transactions with Iran's Central Bank.
July 1: A European oil ban on Iranian crude oil imports is scheduled to begin.