The head of the Lebanese Shiite movement Hezbollah warned on Friday that if there was a war against Iran the whole Middle East region would "erupt", amid escalating US-Iranian tensions.
U.S. President Donald "Trump, his administration, and his intelligence know well that any war on Iran will not remain confined to Iran's borders", Hassan Nasrallah said.
"Any war on Iran will mean the whole region will erupt," said the head of the Iran-backed movement in a televised speech, explaining that such a war was therefore unlikely.
"And any American forces and American interests will be permissible" as a target, he said.
Hezbollah is listed as a "terrorist group" by the United States, and has fought several wars with US-ally Israel to the south of Lebanon.
Nasrallah on Friday also slammed a proposed U.S. peace deal to end the Israeli-Palestinian conflict that Trump has dubbed "the deal of the century".
"It's a void deal... a historic crime," he said of the plan, that has already been rejected by the Palestinians as it is expected to largely favour Israel.
"This deal is a loss of Palestinian, Arab, and Islamic rights," Nasrallah said.
Thousands of Iranians joined annual rallies in support of the Palestinian cause on Friday, also rejecting the US peace plan.
Trump's son-in-law Jared Kushner has been drafting the long-awaited peace plan, the economic aspects of which are to be presented at a conference in Bahrain next month.
The United Nations earlier on Friday said it would not be taking part in that meeting on June 25 and 26 in Manama.
Gulf countries in Mecca expressed "support for the U.S. strategy towards Iran", which includes crippling sanctions and deploying an aircraft carrier task force, B-52 bombers and an amphibious assault ship to the Gulf.
Nasrallah warned that Hezbollah was a force to reckon with.
"We have precision missiles in Lebanon, and enough to be able to change the face of the region," he said.
The movement has been backing the Damascus regime in the civil war in neighboring Syria, and stands accused of also backing rebels in the conflict in Yemen.