The head of the UN nuclear watchdog agency called on Iran to explain tunnels built around a nuclear site but expressed optimism about US-Iran talks. The International Atomic Energy Agency (IAEA) has been raising concerns about the tunnels and has requested clarification from Iran. The IAEA director general, Rafael Grossi, stated that Iran has a unique stance of not needing to inform the agency ahead of time. Grossi also mentioned that Iranian and IAEA experts will meet to discuss the issue and reinstall cameras on nuclear sites. The US and Iran have held two rounds of talks, with a new round of technical talks expected this weekend.