US Vice President Mike Pence described the 1983 bombing of a Marine Corps barracks in Beirut as the opening shots of the "war of terror" Monday, as he issued fresh warnings to Iran and Hezbollah.

Speaking during a ceremony at another building used to house Marines in Washington, Pence berated Tehran and framed the attack that killed 241 Americans as part of a series of outrages that included 9/11.

"Thirty-four years ago today, America was thrust into war with an enemy unlike any we had ever faced," said Pence -- who is the father and brother of US Marines.

"The Beirut barracks bombing was the opening salvo in a war that we have waged ever since -- the global war on terror," he said.

"It's a conflict that has taken American troops across the wider world -- from Lebanon to Libya, from Nigeria to Afghanistan, from Somalia to Iraq, and many other battlefields in between."

Pence's remarks come amid a broad Trump administration effort to ratchet up pressure on Iran.

Since coming to office, Trump has stepped back from a deal curbing Iran's nuclear weapons and vowed to push back against Tehran's influence across the Middle East.

The White House argues the nuclear deal -- forged by president Barack Obama -- resulted in America turning a blind eye to Iran's support of militia groups and terror financing across the region.

"This president will not sit idly by while the ayatollahs in Tehran plot more attacks like the horrific attack that we remember today," Pence said.

Many of Trump's inner circle, from White House Chief of Staff John Kelly to National Security Advisor HR McMaster have tangled with Iranian-backed militia in Iraq during their military service.

According to officials, Pence's appearance came after an invitation transmitted by the National Security Council.

- The main enemy -

But the inclusion of Iran in the "war on terror" is likely to raise questions.

For much of the last two decades, that "war" declared after 9/11 has become synonymous with US efforts to unravel predominantly Sunni terror groups like Al-Qaeda and the Islamic State.

The 1983 attack was blamed on Shia militia group Hezbollah, which is backed by Iran.

"The brutal act that brings us here today was planned and perpetrated by the terrorists of Hezbollah," said Pence, taking aim at the premier Iranian-backed armed group, which remains powerful in Lebanon and Syria.

"Under President Trump's leadership, we've redoubled our commitment to cripple Hezbollah's terrorist network and bring its leaders to justice," Pence said.

Earlier this month, the Trump administration offered $7 million for information that leads to Talal Hamiyah, alleged head of Hezbollah's "External Security Organization."

A further $5 million was offered for leads on Fuad Shukr, "a senior military commander" of Hezbollah in Lebanon, who Pence described as "one of the masterminds behind the bombing of the Marine Corps barracks."

"But as we all know, that terrorist group is merely a proxy for the leading state sponsor of terrorism," Pence said, referring to Iran.

"President Donald Trump has put Iran on notice that we will no longer tolerate their destabilizing activities or their support of terrorism across the region and across the world."

Pence said "Iran's theocratic rulers aided and abetted the Beirut bombers 34 years ago. And even now, Iran praises the attackers and remembers them as martyrs."

"Worse yet, the Iranian regime continues to funnel funds and weapons to its terrorist minions, with the goal of shedding blood and sowing chaos throughout the wider world," the US vice president added.

Source: AFP