On Wednesday, Iran’s Supreme Leader Ali Khamenei threatened “irreparable damage” if the U.S. joins the Israeli conflict.

“The Americans should know that any U.S. military intervention will undoubtedly be accompanied by irreparable damage,” Khamenei said in a televised address. “The U.S. entering in this matter [war] is 100% to its own detriment. The damage it will suffer will be far greater than any harm that Iran may encounter.”

The Israel-Iran conflict has entered its ninth day and shows no signs of slowing down.

Israel’s initial strikes on Iran, conducted in the early hours of June 13, targeted multiple nuclear and military sites, amid rising concerns of Iran’s nuclear capabilities. Israeli Prime Minister Benjamin Netanyahu said the strikes, part of Operation Rising Lion, “would continue for as many days as it takes to remove this threat.”