Six U.S. service members have now been killed as fighting in the Middle East intensifies, with Iran and its proxy forces launching retaliatory strikes against Israel and Arab states while U.S. and Israeli forces continue targeting sites inside Iran.

U.S. Central Command said Monday afternoon that two previously unaccounted-for service members were confirmed dead after their remains were recovered from a facility struck during Iran’s initial attacks in the region. Earlier, officials had announced that a fourth service member had succumbed to injuries sustained in the attacks.

In a separate incident, three American fighter jets were accidentally shot down by Kuwaiti air defenses, U.S. military officials said Monday. All six crew members ejected safely.

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Meanwhile, Defense Secretary Pete Hegseth said during a press briefing Monday that strikes will continue to combat what he described as Iran’s “stubborn and self-evident nuclear pursuits.”

“Iran was building powerful missiles and drones to create a conventional shield for their nuclear blackmail ambitions,” Hegseth said.

“The former regime had every chance to make a peaceful and sensible deal,” he added. “But Tehran was not negotiating — they were stalling, buying time to reload their missile stockpiles and restart their nuclear ambitions. Their goal: hold us hostage, threatening to strike our forces.”

At least 555 people have been killed in Iran since the start of the latest round of strikes, according to Iranian officials.

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In Israel, Iranian-backed Hezbollah militants claimed responsibility for deadly strikes in the country. A senior Iranian official said the U.S. and Israel “crossed a red line and must pay the price” for Khamenei’s killing.

With Khamenei dead, a 66-year-old cleric has been selected to join a three-member council that will govern Iran until a new Supreme Leader is appointed. Trump said Sunday he has agreed to talk with potential new Iranian leadership, but Iran does not appear, at this point, ready to engage in talks with the U.S.

Iran has launched strikes against Israel and against U.S. bases in gulf nations. Attacks also damaged several ships in the Strait of Hormuz.