Tokyo | The head of the UN's nuclear agency on Wednesday signaled that Iranian nuclear enrichment sites would be visited by his inspectors, a key component in the interim deal between the United States and Iran to reach an end to the war.

International Atomic Energy Agency (IAEA) head Rafael Mariano Grossi made the comments in Tokyo.

"Whether this happens the day after tomorrow or in one week or in 10 days, it's important, but not essential," Grossi told journalists. "This is going to happen." On Tuesday, Iran and the US disputed whether or not bombed enrichment sites would be inspected. That's key for the deal, which calls for Iran's stockpile of uranium to be "downblended" from highly enriched levels.