Leaders from Germany, France and the United Kingdom have spent the past several weeks meeting with Iranian officials, seeking a solution ahead of a deadline this week on a threat to reimpose U.N. sanctions.

Qalibaf's admission marks a rare departure from Tehran's usual narrative of military invulnerability, which it maintained for months before the conflict, with threats to Israel and the U.S. When Israel launched airstrikes in June, Iran's defenses did not stop those attacks effectively.