WASHINGTON − Iran's supreme leader warned of "irreparable damage" to the U.S. if it joins Israel's air war against Tehran's nuclear program. Ayatollah Ali Khamenei rejected PresidentDonald Trump's demand for unconditional surrender, as Iranians jammed the highways out of Tehranfleeing intensified Israeli airstrikes. In a recorded speech played on television June 18, his first appearance since Friday, Khamenei, 86, said Washington "should know that any U.S. military intervention will undoubtedly be accompanied by irreparable damage." "Intelligent people who know Iran, the Iranian nation and its history will never speak to this nation in threatening language because the Iranian nation will not surrender," he said. Trump on June 17 personally threatened Khamenei, caling him an "easy target. Trump has veered from proposing a swift diplomatic end to the war to suggesting the United States might join it. In social media posts on Tuesday he mused about killing Khamenei, then demanded Iran's "UNCONDITIONAL SURRENDER!" Follow along with USA TODAY's live coverage of the conflict. As Israel and Iran trade blows in anescalating aerial war, Israel has its sights trained on taking outIran's nuclear facilities– and it wants theU.S. military's help. Israel wants the Pentagon to drop the bombs because their penetrating weapons cannot reach the depth necessary to destroy underground facilities, according to a U.S. official who was not authorized to speak publicly. Fully demolishing Iran's nuclear facilities would require 30,000-pound Massive Ordnance Penetrator (MOP) bombs, or "bunker-busters," which Israel's military doesn't have. But Israel could use smaller penetrating weapons to collapse the entry ways to Iran's underground nuclear facilities, Scott Murray, a retired Air Force colonel and intelligence officer, told USA TODAY. Israel could then effectively bar Iran from recovery work at the sites. "Think of it as a no-work zone patrolled from above," he said. "Air superiority buys incredible capability and flexibility." -Cybele Mayes-Osterman and Tom Vanden Brook Israel's National Security Advisor Tzachi Hanegbi offered the clearest signal yet about the goals of Israel's air campaign, telling local Channel 12 News on June 17 the military is going after the hardest target in Iran: TheFordo nuclear enrichment plant. "This operation will not conclude without a strike on the Fordo nuclear facility," Hanegbi said. Fordo,built into a mountainto withstand airstrikes, has 1,000 centrifuges used to enrich uranium. Hanegbi made clear Israel's war would only end after Fordo was hit. Analysts say that would take a U.S."bunker buster" bomb, dropped from an American plane. But Hanegbi said Israel was ready to go it alone. "We're not trying to convince the Americans to join," he said. "The prime minister has a close and intimate dialogue with President Trump, but we never received any promise the U.S. would take part." Hanegbi added the plan is "entirely blue and white" - fully Israeli, without external military support. -Kim Hjelmgaard This article originally appeared on USA TODAY:Iran-Israel live updates: Supreme leader warns US over joining war
