President Trump stated Tuesday that Iran would face “much greater destruction” if the conflict continues, warning, “they haven’t seen anything yet.”

“If we left today, it would take them decades to rebuild, and I don’t believe they could ever rebuild. And honestly, they haven’t seen anything yet. We’ve been nice,” Trump said in the Oval Office.

The president’s remarks followed the loss of at least three U.S. service members over the weekend. Trump has vowed to avenge their deaths and revived threats of extensive assaults on Iranian infrastructure, including power plants and bridges.

Trump threatened devastation while also leaving the door open for diplomacy. Disagreements over sea lanes in the Strait of Hormuz reportedly derailed a memorandum of understanding signed last month with Tehran.

Trump suggested that Iran was “probably” attempting to influence the midterm elections by reviving the conflict. However, he asserted that “behind the scenes” Iranian officials “want to meet desperately to try and end it because they’re getting decimated.”

Aerial view of an explosion at an unknown location during what U.S. Central Command states are strikes on Iran.