Iran signals possible change in its nuclear doctrine

Iran's Supreme Leader, Ayatollah Ali Khamenei, vowed a "a tooth-breaking response" against Israel and the United States on Saturday "for what they are doing against Iran" and its proxies.

The comments came a day after Kamal Kharrazi, an adviser to Khamenei, said Iran has the capacity to produce nuclear weapons and is prepared to change its policies on using them if faced with an existential threat, as the the country engages in a high-stakes tit-for-tat with Israel.

Kharrazi also said the country is likely to increase the range of its ballistic missiles.

“If an existential threat arises, Iran will modify its nuclear doctrine, we have the capability to build weapons and have no issue in this regard,” Kharrazi told the Lebanese broadcaster Al Mayadeen Friday.

Kharrazi added that "the only thing currently prohibiting this is the leader’s fatwa." Khamenei issued a fatwa, or religious ruling, against nuclear weapons in 2003.

In a statemnet on Saturday, General Mohammad Naeini, a spokesperson for Iran's Revolutionary Guard, added to a rising chorous of escalatory remarks from Iranian officials, saying “a decisive and strong response will be given to the enemy’s new aggression. The response will be beyond the enemy’s comprehension, strategic, and powerful.”

“The enemy must learn its lesson that it cannot engage in any act of hostility without receiving a crushing response in return,” he said, referring to Israel.

CIA Director William Burns said earlier in October that the United States had no evidence that Iran has decided to build a nuclear weapon, but that Iran could quickly — within a week or so — secure enough fissile material for an atomic bomb if it chose to, and there would be less time for the world to respond.

A State Department spokesperson told NBC News Friday that the U.S. remains very concerned with Iran’s nuclear activities.

“The President has made clear: We are committed to never letting Iran obtain a nuclear weapon—and we are prepared to use all elements of national power to ensure that outcome,” the spokesperson said.

The spokesperson added that the U.S. intelligence community continues to assess that the supreme leader has not made a decision to resume its nuclear weapons program.

“That said,” the spokesperson added, “we take any nuclear escalation by Iran incredibly seriously and will respond accordingly.”

On Friday, the Pentagon said it will deploy B-52 bombers, fighter jets, refueling aircraft and Navy destroyers to the Middle East in a readjustment of military assets as the Abraham Lincoln carrier strike group prepares to leave the region.

“Should Iran, its partners, or its proxies use this moment to target American personnel or interests in the region, the United States will take every measure necessary to defend our people,” Pentagon spokesperson Air Force Major General Patrick Ryder said in a statement.

Iran has long denied it was seeking a nuclear weapons program since abandoning it after Khamenei's 2003 fatwa.

On Thursday, Netanyahu said Israel had unprecedented freedom of action after the recent airstrikes against Iran.

“We can reach any place in Iran as necessary,” he said in a speech. “The supreme goal I gave to the Israel Defence Forces and the security branches is to prevent Iran from achieving a nuclear weapon.”

Israel hit Iran with three waves of predawn strikes on military targets last Saturday, in what U.S. officials and others had hoped would be the last shot in a hostile exchange between the two regional powers.

The strikes came weeks after Iran launched a barrage of missiles at Israel in retaliation for its assassinations of leaders of Hamas and Iran-backed Hezbollah. The escalation came as Israel refocused from the war in Gaza triggered by the Oct. 7, 2023 terror attacks to fight the Lebanese militia and political group with whom it had been trading blows for a year.

Saturday's comments from Supreme Leader Khamenei, made on the eve of anniversary of the 1979 storming of the American embassy in Tehran, are the latest sign that Iran may not let Israel's strikes go without response.

Iran had initially downplayed the impact of Israel’s strikes on its military facilities, but in recent days has begun to voice increasingly belligerent rhetoric.

Several Iranian officials made separate statements earlier this week. Hossein Salami, commander of the IRGC, threatened “an unimaginable response” for Israel's attack, Tasnim, the semiofficial Iranian news agency reported.

Deputy commander of IRGC, Ali Fadavi said “Iran’s response to Israel’s aggression is certain.”

“For over 40 years we have never left an act of aggression unanswered, and we have the capability to target all of the Zionist regime’s assets in a single operation,” Fadavi added, referring to Israel.

Kamal Kharrazi's statement on Friday referenced Iran's historical reliance on Europe as a diplomatic lifeline, which appears to have deteriorated.

“In the matter of missile range, we have so far considered Western sensitivities, particularly those of the Europeans,” he said. “When they disregard our sensitivities, especially regarding the territorial integrity of the Islamic Republic of Iran, there is no reason for us to consider their concerns.”

“There is a possibility that the range of Iran’s missiles may increase,” he said.

In 2015, during the administration of President Barack Obama, it sealed a nuclear deal with the United States and other world powers, promising to curb its nuclear program in exchange for billions of dollars in sanctions relief.

But in 2017, then-President Donald Trump withdrew from the plan, saying it did not curtail Iran’s ballistic missile program or the influence of Iran’s powerful proxies in the region. Since the U.S. exit, Iran has steadily blown through the restrictions on its nuclear activities and blocked international inspectors from seeing some nuclear sites.

Aurora Almendral is a London-based editor with NBC News Digital.