Iran's parliament speaker Mohammad Baqer Qalibaf said on Sunday that militant groups would carry on confronting Israel with Tehran's help following the killing of Hezbollah chief Sayyed Hassan Nasrallah, Iranian state media reported.
An alliance known as the Axis of Resistance, built up over decades with Iranian support, includes the Palestinian group Hamas, Hezbollah in Lebanon, Yemen's Houthis, and various Shi'ite Muslim armed groups in Iraq and Syria.
Israel said it killed Nasrallah in an airstrike on Hezbollah's headquarters in Beirut's southern suburbs on Friday. Hezbollah confirmed he had been killed, without saying how.
"We will not hesitate to go to any level in order to help the resistance," Qalibaf said.
He also issued a warning to the United States.
"The U.S. is complicit in all of these crimes and...has to accept the repercussions," he said.
Also commenting on Nasrallah's killing, Iranian Foreign minister Abbas Araqchi said Israel "will not rest" and the action would not go unanswered, state media reported on Sunday. He said the region was in a dangerous situation.
Iran Revolutionary Guards' deputy commander Abbas Nilforoushan was also killed in the Israeli strikes on Beirut on Friday, Iranian media reported on Saturday.