It’s been a week since Iran shot down a U.S. military drone—and neither side seems to have any interest in calming tensions. In its latest warning, Iran has told the Trump administration that any further violation of its borders will result in a “stronger” retaliation than the drone shooting. The U.S. denies the drone crossed into Iran’s airspace. Parliamentary Speaker Ali Larijani suggested the drone strike was a good learning process for the U.S. to make it think twice about antagonizing Iran. “The downing of their drone was a good experience for them to avoid any aggression against our borders,” Larijani was quoted as saying. “Iran’s reaction will be stronger if they repeat their mistake of violating our borders.” Iran and the U.S. disagree on where the drone was when it was shot down—Iran thinks it was in their airspace, but the U.S. says it was international airspace when the attack was ordered.