"The blow was delivered by the wicked and criminal Zionist ruling group, which is the vile and hostile enemy of the Iranian nation," Khamenei said in a message commemorating the 40th day after the killing of the senior military commanders and scientists.
"Without a doubt, the loss of commanders such as the martyrs Baqeri, Salami, Rashid, Hajizadeh, Shadmani and other military personnel, as well as scientists like the martyrs Tehranchi, Abbasi and other scholars, is heavy for any nation, but the foolish and shortsighted enemy did not achieve its goal," he added.
Khamenei said the Islamic Revolution's military and scientific progress would soon "press forward faster than before toward lofty horizons."
The defiant remarks by Iran's 86-year-old veteran theocrat signal no retreat from decades of official hostility to Israel and the United States despite the recent military setback and mounting economic problems.
Israel launched a surprise military campaign on Iran on June 13 that hit military, nuclear, and civilian sites nationwide, kiling hundreds of senior Iranian military commanders, nuclear scientists and civilians.
Iran retaliated with ballistic missile and drone attacks on Israel, killing 27 civilians. Iran says 1,062 people were killed during the 12-day conflict with Israel, including 786 military personnel and 276 civilians.
During the June conflict, Israel's air force took control of Iranian airspace, delivering a significant blow to the country's air defenses, while Iran's armed forces responded with successive waves of missile and drone attacks on Israeli territory.
In his message on Friday, Khamenei urged Iran's military commanders to "increasingly equip the country with tools for safeguarding security and national independence."
He also called for the acceleration of the country's "scientific and technological advancement in all sectors."
Israeli military officials say that 120 air defense systems were destroyed or disabled since the first wave of attacks—around a third of Iran’s pre-war total.
Long-range systems, including Russian-supplied S-300s and Iran’s Bavar-373 batteries, were among those targeted.