New Delhi, April 17 -- The head of the U.N.'s nuclear watchdog said Wednesday that "very detailed" measures to verify Iran's nuclear activities must be included in a potential U.S.-Iran agreement to end their war in the Middle East.

International Atomic Energy Agency Director General Rafael Grossi stressed the need for the thorough verification regime for Iran's nuclear program, as U.S. President Donald Trump said Tuesday that a second round of talks with Iran could happen over the next two days.

The Trump administration has said that preventing Iran from gaining a nuclear weapon is a key war aim. Iran has previously said it isn't developing such weapons but rejected limits on its nuclear program.

Last weekend in Pakistan, an initial r...