WASHINGTON/DUBAI: The US expressed “deep concern” Tuesday over the progress Iran is making on its nuclear program and ballistic missile capability, after Tehran said it has begun enriching uranium to 60 percent at a second facility. “We’re going to make sure we have all options available to the president,” White House national security spokesman John Kirby told a briefing in Washington. “We certainly have not changed our view that we will not allow Iran to achieve a nuclear weapons capability.” Iran meantime publicized that it had moved ahead on uranium enrichment that Western governments worry is part of a covert nuclear weapons program. “Iran has started producing uranium enriched to 60 percent at the Fordo plant for the first time,” Iran’s ISNA news agency reported, a development then confirmed by Atomic Energy Organization of Iran chief Mohammad Eslami. An atomic bomb requires uranium enriched to 90 percent, so 60 percent is a significant step toward weapons-grade enrichment. The heavily protected Fordo plant around 190 km south of Tehran was built deep underground in a bid to shield it from air or missile strikes by Iran’s enemies. Iran in April announced that its older facility at Natanz, southeast of Fordo, had ramped uranium enrichment to 60 percent. Meanwhile, investigators have concluded that an Iranian drone was used to bomb an oil tanker linked to an Israeli billionaire last week, the US Navy said on Tuesday. The drone attack on the Liberian-flagged oil tanker Pacific Zircon last Tuesday off the coast of Oman appears to be part of the long-running shadow war between Israel and its archenemy Iran that has included the targeting of Israeli-linked ships in strategic Mideast waterways. The Navy said explosives experts boarded the ship to assess the damage, including a 30-inch-wide hole punched in its side, and to collect debris and bomb residue. The evidence was taken to a lab at the headquarters of the US Fifth Fleet in Bahrain. Navy investigators concluded that the drone used was an Iranian Shahed-136, the same kind of bomb-carrying drone Iran has supplied to Russia in its war on Ukraine. Iranian drones were used by the Houthis earlier this year, the Navy said.