Deadly Israeli attacks that blew up Hezbollah radios and pagers crossed all red lines, the leader of the heavily armed Iran-backed Lebanese movement said on Thursday, as the United States called for restraint and urgent de-escalation.

The absence of a full-blown war in Lebanon has been touted as a core U.S. achievement, but now Washington’s grip on the crisis appears more tenuous than ever.

Hassan Nasrallah refused to say when or how Hezbollah would take revenge. As he spoke, Israeli fighter jets swooped low over Beirut.