Vance made the remarks during a special public Q&A programme on a US news channel, where he answered questions about the growing human and economic costs of the conflict.
Addressing security at American military installations, Vance admitted that gaps existed and said some information did not always reach him. He assured the audience that the administration would take every failure seriously.
The vice president also acknowledged that the deployment of US troops had exposed weaknesses in military strategy. He said some decisions about where personnel were stationed had been major mistakes and could have been handled better, adding that changes had since been made.
Vance also highlighted the growing threat posed by low-cost drones, saying the US military had revised its approach to better protect personnel and prevent further casualties.
Asked why Washington had not secured a decisive victory despite President Donald Trump’s initial expectations, Vance maintained that the United States had achieved decisive gains in certain areas.
However, he acknowledged that the war’s ultimate outcome would also depend on Iran’s actions, saying the opposing side’s decisions remained an important factor.
Defending the administration’s strategy, Vance said Washington was seeking firm and concrete guarantees from Iran that it would not revive its nuclear programme.
His comments highlighted the military and strategic challenges facing the United States as the conflict continues, as well as Washington’s efforts to obtain assurances regarding Iran’s nuclear ambitions.