A team of International Atomic Energy Agency (IAEA) inspectors is in Iran with plans to visit a uranium mine and a uranium-processing facility on May 6.
Tehran says it can declare after those inspections that it has fulfilled a February agreement with the IAEA, the UN's nuclear watchdog.
That has raised hopes for a breakthrough on a permanent agreement limiting Iran’s nuclear program and easing Western concerns that Tehran is trying to secretly develop nuclear weapons or a bomb-making capability.
In New York, negotiators from Iran, Britain, China, France, Germany, Russia, and the United States are meeting throughout this week to try to resolve the most difficult issues on a permanent accord before a July 20 deadline established under a temporary agreement in November.
The New York talks come ahead of the next ministerial-level negotiations in Vienna on May 13.
Based on reporting by Reuters, AP, and IRNA