SEOUL, SOUTH KOREA — International Atomic Energy Agency Director General Rafael Grossi said in Seoul, South Korea, that measures to verify Iran's nuclear activities must be included in any U.S.-Iran agreement to end their war in the Middle East. Grossi said that any agreement on nuclear technology requires detailed verification mechanisms.

"Iran has a very ambitious, wide nuclear program so all of that will require the presence of IAEA inspectors. Otherwise, you will not have an agreement. You will have an illusion of an agreement," he said.

He said that Iran's uranium stockpile could allow the country to build as many as 10 nuclear bombs if it decided to weaponize its program. The IAEA has stated that Iran has a stockpile of 440.9 kilograms of uranium enriched up to 60% purity. Under the agency's guidelines, highly enriched nuclear material should be verified every month.

Iran has not allowed the IAEA access to its nuclear facilities that were bombed by Israel and the United States during a 12-day war in June. According to a confidential IAEA report, the agency cannot verify whether Iran has suspended all enrichment-related activities or determine the size of Iran's uranium stockpile at the affected facilities.

Iran has long insisted that its nuclear program is peaceful and has said that it is not developing nuclear weapons. The country has rejected limits on its nuclear program. The IAEA says that Iran had an organized nuclear weapons program until 2003.

An initial round of talks between the U.S. and Iran held last weekend in Pakistan failed to produce an agreement. The White House said that Iran's nuclear ambitions were a central sticking point in the talks. An Iranian diplomatic official speaking on condition of anonymity denied that the negotiations failed over Iran's nuclear ambitions.

The Trump administration has said that preventing Iran from gaining a nuclear weapon is a key war aim. A second round of talks with Iran could happen over the next two days, according to statements from the administration.