Israel Prime Minister Benjamin Netanyahu addressed the Munich Security Conference on Sunday and focused on the Iranian threat.

“We will act, if necessary, not just against Iran’s proxies but against Iran itself,” warned Netanyahu, also saying that “Israel will not allow the regime to put a noose of terror around our neck.”

During the speech, Netanyahu held up a piece of the Iranian drone that the Israeli army had shot down as it flew into Israeli airspace earlier this month. “Iran denies that it committed an act of aggression against Israel last week, that it sent a drone into our airspace to threaten our people. Here’s a piece of that Iranian drone, or what’s left of it after we shot it down,” he said.

As he held up the fragment, Israel’s premier called out Iranian Foreign Minister Mohammad Javad Zarif, saying: “Mr. Zarif, do you recognize this? You should. It’s yours. You can take back with you a message to the tyrants of Tehran: Do not test Israel’s resolve.”

Hours later, Zarif responded to Netanyahu by calling his presentation a “cartoonish circus.”

Netanyahu also warned that as the power of ISIS contracts, Iran is moving in, and “it is trying to establish this continuous empire surrounding the Middle East from the south in Yemen but also trying to create a land bridge [from] Iran, Iraq, Syria, Lebanon and Gaza.”