June 27 (UPI) -- Iran officially acknowledged its nuclear sites had sustained "serious and significant damage" from U.S. air and missile strikes last weekend.

Iranian Foreign Minister Abbas Araghchi said that while the extent of the damage was still being assessed by the Atomic Energy Organization of Iran, it was undeniable that the losses were substantial and that the country's nuclear facilities "have been seriously damaged."

The admission by Araghchi in an interview with Iranian state television on Thursday came amid conflicting reports on the efficacy of the unprecedented military action launched by the United States against three nuclear sites on June 21.

Earlier Thursday, Iranian leader Ayatollah Ali Khanamei claimed the opposite of his foreign minister, saying damage to the sites had been minimal and instead hailing the "damage inflicted" by Tehran's "victorious" retaliatory strike on the United States' Al-Udeid Air Base in Qatar on Monday.

The administration of U.S. President Donald Trump has said the strikes using 30,000-pound bunker-buster bombs and long-range Tomahawk cruise missiles "completely and fully obliterated" Iran's nuclear program -- although public briefings have focused on the "primary site," a key underground uranium enrichment plant at Fordow, with few details forthcoming on the facilities at Natanz and Esfahan.