The Pentagon’s chief spokesman said on Wednesday that the U.S. strikes against the Iranian nuclear program had set the program back by two years. His estimate appears to be the most specific information the Trump administration has shared on the extent of the damage caused by the strikes.

U.S. allies “share our sentiments about the degradation of Iran’s nuclear program and the fact we have degraded their program by one or two years … I think we’re thinking closer to two years,” Sean Parnell said at a press conference.

The administration has consistently claimed the strikes completely destroyed the nuclear program. During the briefing, Parnell said that he believed the combination of U.S. and Israeli strikes would be successful in deterring Tehran from continuing its nuclear program in the future. 

“We believe that sending bombers from Missouri, 37 hours on a mission, not a single shot fired on them, took a very strong psychological toll on the Iranian leadership,” Parnell said. “So, when you take the constellation of different things into consideration, we believe Iran’s nuclear capability has been severely degraded, perhaps even their ambition to build a bomb.”

Parnell’s remarks came hours after Iranian Foreign Minister Abbas Araghchi told CBS News that the country’s nuclear facilities were “heavily and severely damaged.” Araghchi maintained that Iran’s enrichment equipment and knowledge base were not impacted, despite Israel assassinating several of the country’s senior nuclear scientists. 

Araghchi also said that Iran’s nuclear agency was still conducting damage assessments at the Fordow, Natanz and Isfahan nuclear sites. This was confirmed by geospatial imagery analysis from the Institute for Science and International Security, which showed crews working to gain access to the underground sections of the facilities.